Substituted pyrido[3,4-b]indoles for the treatment of cartilage disorders

ABSTRACT

The present invention relates to 8-aryl-substituted and 8-heteroaryl-substituted 9H-pyrido[3,4-b]indoles of the formula (I), in which A, E, G, R1 to R6 and R10 are as defined in the claims, which stimulate chondrogenesis and cartilage matrix synthesis and can be used in the treatment of cartilage disorders and conditions in which a regeneration of damaged cartilage is desired, for example joint diseases such as osteoarthritis. The invention furthermore relates to processes for the synthesis of the compounds of the formula (I), their use as pharmaceuticals, and pharmaceutical compositions comprising them.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Phase application under 35 U.S.C. § 371of International Application No. PCT/EP2017/078026, filed Nov. 2, 2017,which claims priority to European Application No. 16306452.0, filed Nov.7, 2016, the disclosures of each of which are incorporated herein byreference in their entireties.

The present invention relates to 8-aryl-substituted and8-heteroaryl-substituted 9H-pyrido[3,4-b]indoles of the formula I,

in which A, E, G, R¹ to R⁶ and R¹⁰ are as defined below, which stimulatechondrogenesis and cartilage matrix synthesis and can be used in thetreatment of cartilage disorders and conditions in which a regenerationof damaged cartilage is desired, for example joint diseases such asosteoarthritis. The invention furthermore relates to processes for thesynthesis of the compounds of the formula I, their use aspharmaceuticals, and pharmaceutical compositions comprising them.

Osteoarthritis, which in the following is also abbreviated as “OA” andsometimes is also referred to as osteoarthrosis, is the most commondegenerative disease which primarily involves cartilage damage injoints. With increasing age, up to 80% of the population is affected.Although clinical signs of the disease are rather heterogeneous,patients suffering from OA generally demonstrate a common pathologicalphenotype. At early disease stages, which are characterized by moderatedegradation of the cartilage lining of the joints, pain is the mostprominent symptom. With progressing degradation of the cartilage andcartilage loss, an increase in pain results that is commonly accompaniedby an increasing deficit in mobility of the affected joints andultimately total immobility and loss of function. As a result ofdegradation of cartilage and cartilage loss, also subchondral structuresstart to change their morphology, leading to remodeling processes of thebone, such as a compaction of bone matter, and to the formation ofcysts. In part patients also show signs of inflammation thatadditionally affects the synovial lining of the joint. At late stages ofthe disease, a total destruction of the joint is observed.

There is still an incomplete understanding of the pathophysiology ofcartilage disorders such as OA, and until today no structure-modifying,or disease-modifying, therapies are available (cf. K. Wang et al.,Expert Opin. Investig. Drugs, 2015, 24, 1539-1556; T. Aigner et al.,Adv. Drug Deliv. Rev. 2006, 58, 128-149). Currently OA is generallytreated with drugs which target pain and inflammation systemically orlocally. Different non-steroidal anti-inflammatory drugs (NSAIDs) areused, as well as glucocorticoids which are administered locally byintra-articular injection. Both therapeutic strategies result in painrelief, but do not halt or reverse the progression of cartilagedestruction. On top of such drug interventions, physical therapy and/orlocal intra-articular injections of hyaluronic acid are applied.Ultimately, a partial or total replacement of an affected joint, such asa knee or hip joint, is the only remaining choice for relieving patientsfrom severe joint pain and restoring joint mobility and function.

Recently evidence has been generated that in particular in early stagesof OA cartilage has still some potential for regeneration andself-healing, and it has been proposed to induce chondrogenesis, i.e.the process by which cartilage is generated, or stimulate cartilagegrowth, in order to reverse, or compensate for, cartilage destruction inOA. This concept was confirmed by recent data from clinical trials withrecombinant human FGF18 (fibroblast growth factor 18, Sprifermin,AS902330), which showed cartilage protective effects in knee OA inhumans (L. S. Lohmander et al., Arthritis Rheumatol. 2014, 66,1820-1831; S. Onuora, Nature Rev. Rheumatol. 2014, 10, 322; WO2008/023063). FGF18 is assumed to stimulate osteoblasts and, via theactivation of chondrocytes, the formation of cartilage, and thus supporthealing, and not merely alleviate symptoms.

Articular cartilage functions as a low-friction, wear-resistant surfacethat covers the ends of bones and supports load transfer and motion ofdiarthrodial joints. These properties and functions of cartilage areowed to the composition of articular cartilage. Cartilage tissue, whichis a kind of connective tissue and besides in joints is also present inintervertebral disks, for example, is built up by and contains aspecialized cell type, the chondrocytes, that produce and maintain anextensive extracellular matrix composed mainly of collagen, mostlycollagen type II and minor amounts of other types of collagen, ofproteoglycans, mostly aggrecan, and of hyaluronic acid. The fibrillarcollagen network and the highly negatively charged aggrecan confertensile strength and compressive stiffness to the tissue (D. Heinegardet al., Nature Rev. Rheumatol. 2011, 7, 50-56). Chondrocytes, which mayaccount to only 2% of the volume of the tissue in normal articularcartilage, maintain homeostasis of the tissue by regulation ofextracellular matrix anabolism and catabolism. This continuousrebuilding of cartilage in an equilibrium of formation and degradationof the matrix, which is present under normal conditions, is disturbed indisease states such as OA, in which catabolic processes predominate.

Besides biomechanically induced modulation of the chondrocytebiosynthetic activity, several soluble factors, such asgrowth/differentiation factors and cytokines, have been identified tomodulate anabolic and catabolic activity of chondrocytes. Anaboliccytokines that are considered to participate in cartilage repairprocesses, are IGF-1 (insulin-like growth factor 1), members of theTGF-β (transforming growth factor β) superfamily (for example TGF-β1,GDF5 (growth/differentiation factor 5), BMP2 (bone morphogenetic protein2), BMP4, BMP7) and FGFs (fibroblast growth factors). bFGF (basicfibroblast growth factor) is the most potent chondrocyte mitogen, andother FGF family members, for example FGF18, may interact with IGF-1 andTGF-β to promote and maintain specific chondrocyte activities dependingon the stage of the chondrocyte cell or differentiation status (M. B.Goldring, Arthritis Rheum. 2000, 43, 1916-1926). In addition to ananabolic, or synthesis promoting function, growth factors and cytokinescan exert an anti-catabolic function. BMP7, which is also known as OP-1(osteogenic protein 1), for example, has been shown to counteract lowdoses of IL-1β (interleukin 1β) by inhibition of the expression ofmetalloproteinases MMP3 (matrix metalloproteinase 3; also known asstromelysin 1) and MMP13 (also known as collagenase 3).

Among the catabolic cytokines, proinflammatory IL-1α and IL-1β as wellas TNF-α (tumor necrosis factor α) are considered key factors which leadto extracellular matrix degradation by induction of the expression ofproteinases, such as MMP3, MMP13, ADAMTS-4 (“A Disintegrin AndMetalloproteinase with Thrombospondin Motifs”-4) and ADAMTS-5, whichfunction as aggrecanase cleaving aggrecan, and by repression of thesynthesis of the extracellular matrix synthesis components collagen IIand aggrecan. Other catabolic cytokines known are IL-18, LIF (leukemiainhibitory factor) and OSM (Oncostatin M). In early osteoarthritis,chondrocytes attempt to repair a disturbed equilibrium of formation anddegradation of the matrix by an endogenous repair process, but duringprogression of OA chondrocytes fail to maintain tissue homoeostasis, andthe balance between anabolic and catabolic activity is lost andcatabolic activity prevails (X. Houard et al., Curr. Rheumatol. Rep.2013, 15, Article 375). Influencing anabolic and/or catabolic activitiesin favor of an increase in cartilage formation by means of appropriateactive agents, similarly as observed with FGF18 in the study referred toabove, offers an opportunity for treating OA.

Furthermore, recent evidence suggests the existence of progenitor cellswithin cartilage which might contribute to a repair response (S.Koelling et al., Cell Stem Cell 2009, 4, 324-335). Therefore,enhancement of chondrogenesis by influencing chondrocyte progenitorcells or mesenchymal stem cells arises as another therapeutic conceptfor treating osteoarthritis. In addition, chondrogenesis in the contextof cell therapy is of relevance for cartilage repair. In particular insuch approaches processes of cell differentiation and gene expressionand influencing them by appropriate agents play a role. The SOX (SRY(sex determining region Y) box, or SRY-related HMG (high mobility group)box) family of transcription factors are the main inducers ofchondrogenic differentiation, in particular SOX-9 which inducesmesenchymal condensation and differentiation of cartilage precursorcells, followed by SOX-5 and SOX-6, which regulate the synthesis ofcartilage matrix genes (B. de Crombrugghe et al., Curr. Opin. Cell Biol.2001, 13, 721-727). However, as indicated above, until today nostructure-modifying therapies for the treatment of disease states likeOA have become available, and there continues to be need for concepts oractive agents, which can stimulate chondrogenesis and lead to cartilageregeneration.

In WO 2010/038153 it has been described that a number of compounds ofvarying structures, mainly natural products such as flavonoidderivatives, are SOX transcription factor activators and stimulatechondrogenesis. In E. S. Hara et al., Biochimie 2013, 95, 374-381, andin JP 2012-171947 it has recently been described that the naturallyoccurring 7-alkoxy-substituted-pyrido[3,4-b]indole harmine(1-methyl-7-methoxy-9H-pyrido[3,4-b]indole or1-methyl-7-methoxy-9H-β-carboline) has a chondrogenic effect. But as theauthors point out, in view of its property profile harmine itself doesnot seem to be a suitable drug substance for the treatment ofdegenerative joint diseases, and some structurally related compounds didnot exhibit an analogous activity.

Surprisingly it has been found that the 8-aryl-substituted and8-heteroaryl-substituted 9H-pyrido[3,4-b]indoles of the formula I arepotent stimulators of chondrogenesis and of cartilage formation, andexhibit other suitable properties and can be designed to exhibit aproperty profile suitable for the intended use, for example with regardto their solubility, which can be desired to be either high or low, inthe latter case allowing for a long residence time in a joint afterintra-articular administration. The compounds of the formula I inducethe synthesis of major articular cartilage matrix components such ascollagen type II and aggrecan in chondrocytes. Furthermore, they lead tostrong induction of SOX-5, SOX-6 and SOX-9. The compounds of the formulaI thus are useful as active agents for regenerating cartilage andtreating joint diseases such as OA, for example.

Various other 9H-pyrido[3,4-b]indoles, which are also designated as9H-β-carbolines, 9H-beta-carbolines or 9H-betacarbolines, have beendescribed. For example, in U.S. Pat. No. 4,631,149 certain9H-pyrido[3,4-b]indoles are disclosed which have antiviral,antibacterial and antitumor activity. In U.S. Pat. No. 5,604,2369H-pyrido[3,4-b]indoles are disclosed which contain an acidic group andinhibit thromboxane synthetase, and are useful for the treatment ofthromboembolic diseases. In WO 01/68648 and WO 03/0395459H-pyrido[3,4-b]indoles are disclosed which inhibit the activity of IκBkinase and are useful for the treatment of cancer and other diseases. InWO 2008/132454 9H-pyrido[3,4-b]indoles are disclosed which are ligandsfor the GABA_(A) receptor and are radiolabeled, and are useful asdiagnostics in CNS disorders. In C. Domonkos et al., RSC Advances 2015,5, 53809-53818, certain 9H-pyrido[3,4-b]indoles carrying an alkoxysubstituent or substituted alkoxy substituent in position 7 of the ringsystem are disclosed which have anticancer activity. In WO 2015/083750certain benzothiazole derivatives and certain 9H-pyrido[3,4-b]indolederivatives carrying an alkoxy-substituent or another substituent linkedvia an oxygen atom in position 7 of the ring system are disclosed whichactivate neuropoiesis via inhibition of dual-specificity tyrosinephosphorylation-regulated kinases (DYRK). 9H-pyrido[3,4-b]indoles whichcarry in the 8-position of the ring system a directly bonded carbocyclicor heterocyclic aromatic group attached via a ring carbon atom, andwhich do not carry a directly bonded aromatic group in another positionof the ring system and do not carry an alkoxy substituent or anothersubstituent linked via an oxygen atom in position 7 of the ring system,have not yet been described, except for the compound8-phenyl-9H-pyrido[3,4-b]indole, which has been prepared in studiesabout transition metal-catalyzed C—H bond functionalizations and isdisclosed in N. Wu et al., Chem. Eur. J. 2014, 20, 3408-3418.

Thus, a subject of the present invention are compounds of the formula Iand the pharmaceutically acceptable salts thereof,

wherein

A is selected from the series consisting of phenyl and a monocyclic orbicyclic, 5-membered to 10-membered, aromatic heterocyclic group, whichcomprises 1 or 2 identical or different hetero ring members selectedfrom the series consisting of N, N(R²⁰), O and S and is bonded via aring carbon atom, wherein phenyl and the heterocyclic group areunsubstituted or substituted on ring carbon atoms by one or moreidentical of different substituents R²¹;

E is a direct bond or a chain consisting of 1 to 5 chain members ofwhich 0, 1 or 2 chain members are identical or different hetero chainmembers selected from the series consisting of N(R²⁵), O and S(O)_(m),and the other chain members are identical or different groupsC(R²⁶)(R²⁷);

G is selected from the series consisting of hydrogen, halogen,(C₁-C₄)-alkyl, cyano and R³⁰;

R¹, R³, R⁴ and R⁶ are independently of each other selected from theseries consisting of hydrogen, halogen and (C₁-C₄)-alkyl;

R² is selected from the series consisting of hydrogen, halogen,(C₁-C₄)-alkyl and (C₁-C₄)-alkyl-O—C(O)—;

R⁵ is selected from the series consisting of hydrogen, halogen,(C₁-C₄)-alkyl, (C₁-C₄)-alkyl-O—, cyano, R⁷—O—C(O)— and R⁸—N(R⁹)—C(O)—;

R⁷, R⁸, R⁹, R²⁰, R²², R²⁵, R³¹, R³³, R³⁴ and R⁴⁰ are independently ofeach other selected from the series consisting of hydrogen and(C₁-C₄)-alkyl;

R¹⁰ is selected from the series consisting of hydrogen, (C₁-C₆)-alkyl,(C₂-C₆)-alkenyl, (C₂-C₆)-alkynyl and (C₃-C₇)-cycloalkyl, wherein alkylis unsubstituted or substituted by 1 or 2 identical or differentsubstituents selected from the series consisting of (C₃-C₇)-cycloalkyl,Het, cyano and (C₁-C₄)-alkyl-O—, wherein all cycloalkyl groups areunsubstituted or substituted by one or more identical or differentsubstituents selected from the series consisting of fluorine and(C₁-C₄)-alkyl;

R²¹ is selected from the series consisting of halogen, (C₁-C₄)-alkyl,(C₁-C₄)-alkyl-O— and cyano, and two groups R²¹ bonded to adjacent ringcarbon atoms in the group A, together with the carbon atoms carryingthem, can form a 5-membered to 7-membered mono-unsaturated ring, whichcomprises 0, 1 or 2 identical or different hetero ring members selectedfrom the series consisting of N(R²²), O and S(O)_(m) and which isunsubstituted or substituted on ring carbon atoms by one or moreidentical or different substituents selected from the series consistingof fluorine and (C₁-C₄)-alkyl;

R²⁶ and R²⁷ are independently of each other selected from the seriesconsisting of hydrogen, fluorine, (C₁-C₄)-alkyl and hydroxy, and in oneor two groups C(R²⁶)(R²⁷) the groups R²⁶ and R²⁷ bonded to the samecarbon atom together can be oxo;

R³⁰ is a monocyclic or bicyclic, 3-membered to 10-membered ring, whichis saturated or unsaturated and comprises 0, 1, 2 or 3 identical ordifferent hetero ring members selected from the series consisting of N,N(R³¹), O and S(O)_(m), and which is unsubstituted or substituted onring carbon atoms by one or more identical or different substituentsR³²;

R³² is selected from the series consisting of halogen, (C₁-C₄)-alkyl,hydroxy, oxo, (C₁-C₄)-alkyl-O—, cyano, R³³—N(R³⁴)— and Het;

Het is a monocyclic, 4-membered to 7-membered, saturated heterocyclicgroup, which comprises 1 or 2 identical or different hetero ring membersselected from the series consisting of N, N(R⁴⁰), O and S(O)_(m), andwhich is unsubstituted or substituted on ring carbon atoms by one ormore identical or different substituents selected from the seriesconsisting of fluorine and (C₁-C₄)-alkyl;

m is selected from the series consisting of 0, 1 and 2, wherein allnumbers m are independent of each other and can be identical ordifferent;

wherein all alkyl groups, independently of any other substituents whichcan be present on an alkyl group, can be substituted by one or morefluorine substituents;

provided that the compound of the formula I is not8-phenyl-9H-pyrido[3,4-b]indole.

If structural elements such as groups, substituents or numbers, likealkyl groups, substituents R²¹ or the numbers m, for example, can occurseveral times in the compounds of the formula I, they are allindependent of each other and can in each case have any of the indicatedmeanings, and they can in each case be identical to or different fromany other such element. In a dialkylamino group, for example, the alkylgroups can be identical or different.

Alkyl groups, i.e. saturated hydrocarbon residues, can be linear, i.e.straight-chain, or branched. This also applies if these groups aresubstituted or are part of another group, for example an alkyl-O— group(alkyloxy group, alkoxy group) or an alkyloxy-substituted alkyl group.Depending on the respective definition, the number of carbon atoms in analkyl group can be 1, 2, 3, 4, 5 or 6, or 1, 2, 3 or 4, or any subgroupof these numbers, such as 2, 3 or 4, or 1, 2 or 3, or 1 or 2, or 1.Examples of alkyl are methyl (C₁-alkyl), ethyl (C₂-alkyl), propyl(C₃-alkyl) including n-propyl and isopropyl, butyl (C₄-alkyl) includingn-butyl, sec-butyl, isobutyl and tert-butyl, pentyl (C₄-alkyl) includingn-pentyl, 1-methylbutyl, isopentyl, neopentyl and tert-pentyl, and hexyl(C₆-alkyl) including n-hexyl, 3,3-dimethylbutyl and isohexyl. Examplesof alkyl-O— groups are methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy,isobutoxy, tert-butoxy, n-pentoxy. A substituted alkyl group can besubstituted in any positions, provided that the respective compound issufficiently stable and is suitable as a pharmaceutical active compound.The prerequisite that a specific group and a compound of the formula Iare suitable as a pharmaceutical active compound, applies in generalwith respect to the definitions of all groups in the compounds of theformula I.

Independently of any other substituents which can be present on an alkylgroup, and unless specified otherwise, alkyl groups can be substitutedby one or more fluorine substituents, for example by 1, 2, 3, 4, 5, 6,7, 8, 9, 10, 11, 12 or 13 fluorine substituents, or by 1, 2, 3, 4 or 5fluorine substituents, or by 1, 2 or 3 fluorine substituents, or by anyother number of fluorine substituents, which can be located in anypositions of the alkyl group. I.e., independently of any othersubstituents which can be present on an alkyl group, an alkyl group canbe unsubstituted by fluorine substituents, i.e. not carry fluorinesubstituents, or substituted by fluorine substituents, wherein all alkylgroups in the compounds of the formula I are independent of one anotherwith regard to the optional substitution by fluorine substituents. Forexample, in a fluoro-substituted alkyl group one or more methyl groupscan carry three fluorine substituents each and be present astrifluoromethyl groups, and/or one or more methylene groups (—CH₂—) cancarry two fluorine substituents each and be present as difluoromethylenegroups. The explanations with respect to the substitution of a group byfluorine also apply if the group additionally carries other substituentsand/or is part of another group, for example of an alkyl-O— group.Examples of fluoro-substituted alkyl groups are trifluoromethyl (CF₃),fluoromethyl, difluoromethyl, 2-fluoroethyl, 1-fluoroethyl,1,1-difluoroethyl, 2,2,2-trifluoroethyl, pentafluoroethyl,3,3,3-trifluoropropyl, 2,2,3,3,3-pentafluoropropyl, 4,4,4-trifluorobutyland heptafluoroisopropyl. Examples of fluoro-substituted alkyl-O— groupsare trifluoromethoxy (CF₃—O—), 2,2,2-trifluoroethoxy, pentafluoroethoxyand 3,3,3-trifluoropropoxy. With respect to all groups or substituentsin the compounds of the formula I which can be an alkyl group that cangenerally contain one or more fluorine substituents, the group CF₃, or arespective group such as CF₃—O—, and other specific fluorine-substitutedgroups, may be included in the definition of the group or substituent asexample of groups or substituents containing fluorine-substituted alkyl.

The above explanations with respect to alkyl groups applycorrespondingly to alkyl groups which in the definition of a group inthe compounds of the formula I are bonded to two adjacent groups, orlinked to two groups, and may be regarded as divalent alkyl groups(alkanediyl groups, alkylene groups), like in the case of the alkyl partof a substituted alkyl group or in the case of the chain E, if E doesnot contain a heteroatom chain member. Thus, such groups can also belinear or branched, the bonds to the adjacent groups can be located inany positions and can start from the same carbon atom or from differentcarbon atoms, and they can be unsubstituted or substituted by fluorinesubstituents independently of any other substituents. Examples of suchdivalent alkyl groups are —CH₂—, —CH₂—CH₂—, —CH₂—CH₂—CH₂—,—CH₂—CH₂—CH₂—CH₂—, —CH(CH₃)—, —C(CH₃)₂—, —CH(CH₃)—CH₂—, —CH₂—CH(CH₃)—,—C(CH₃)₂—CH₂—, —CH₂—C(CH₃)₂—. Examples of fluoro-substituted divalentalkyl groups, which can contain 1, 2, 3, 4, 5 or 6 fluorinesubstituents, for example, are —CHF—, —CF₂—, —CF₂—CH₂—, —CH₂—CF₂—,—CF₂—CF₂—, —CF(CH₃)—, —C(CF₃)₂—, C(CH₃)₂—CF₂—, —CF₂—C(CH₃)₂—.

The above explanations with respect to alkyl groups applycorrespondingly to unsaturated hydrocarbon residues, i.e. alkenylgroups, which in one embodiment of the invention contain one doublebond, and alkynyl groups, which in one embodiment of the inventioncontain one triple bond. Thus, for example, alkenyl groups and alkynylgroups can likewise be linear or branched. Double bonds and triple bondscan be present in any positions. The number of carbon atoms in analkenyl group and an alkynyl group can be 2, 3, 4, 5 or 6, or anysubgroup of these numbers, such as 2, 3, 4 or 5, or 3, 4 or 5, or 2, 3or 4, for example. Examples of alkenyl groups are ethenyl (vinyl),prop-1-enyl, prop-2-enyl (allyl), but-1-enyl, but-2-enyl, but-3-enyl,2-methylprop-2-enyl, 3-methylbut-2-enyl, hex-3-enyl, hex-4-enyl,4-methylpent-3-enyl. Examples of alkynyl groups are ethynyl,prop-1-ynyl, prop-2-ynyl (propargyl), but-2-ynyl, but-3-ynyl,pent-2-ynyl, 4-methylpent-2-ynyl, hex-2-ynyl, hex-3-ynyl. In oneembodiment of the invention, alkenyl groups and alkynyl groups containat least three carbon atoms and are bonded to the remainder of themolecule via a carbon atom which is not part of a double bond or triplebond.

The number of ring carbon atoms in a (C₃-C₇)-cycloalkyl group can be 3,4, 5, 6 or 7, or any subgroup of these numbers, such as 3, 4, 5 or 6, or5, 6 or 7, or 3, 4 or 5, or 3 or 4, for example. Examples of cycloalkylare cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl.

Cycloalkyl groups can be substituted by one or more (C₁-C₄)-alkylsubstituents, for example by 1, 2, 3 or 4, or 1, 3 or 3, or 1 or 2,identical or different (C₁-C₄)-alkyl substituents, for example by methylgroups, which can be located in any positions. I.e., cycloalkyl groupscan be unsubstituted by (C₁-C₄)-alkyl substituents, i.e. not carry(C₁-C₄)-alkyl substituents, or substituted by (C₁-C₄)-alkylsubstituents. Examples of such alkyl-substituted cycloalkyl groups are1-methylcyclopropyl, 2,2-dimethylcyclopropyl, 1-methylcyclopentyl,2,3-dimethylcyclopentyl, 1-methylcyclohexyl, 4-methylcyclohexyl,4-isopropylcyclohexyl, 4-tert-butylcyclohexyl,3,3,5,5-tetramethylcyclohexyl.

Independently of (C₁-C₄)-alkyl substituents, cycloalkyl groups can besubstituted by one or more fluorine substituents, for example by 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or 13 fluorine substituents, or 1, 2, 3,4 or 5 fluorine substituents, or 1, 2 or 3 fluorine substituents, or 1or 2 fluorine substituents, which can be located in any positions andcan also be present in a (C₁-C₄)-alkyl substituent. I.e., cycloalkylgroups can be unsubstituted by fluorine substituents, i.e. not carryfluorine substituents, or substituted by fluorine substituents. Examplesof fluoro-substituted cycloalkyl groups are 1-fluorocyclopropyl,2,2-difluorocyclopropyl, 3,3-difluorocyclobutyl, 1-fluorocyclohexyl,4,4-difluorocyclohexyl, 3,3,4,4,5,5-hexafluorocyclohexyl. Cycloalkylgroups can also be substituted simultaneously by fluorine and alkylsubstituents.

Examples of (C₃-C₇)-cycloalkyl-substituted alkyl groups, from any one ormore of which a (C₃-C₇)-cycloalkyl-substituted alkyl group representingR¹⁰ is selected in one embodiment of the invention, arecyclopropylmethyl-, cyclobutylmethyl-, cyclopentylmethyl-,cyclohexylmethyl-, cycloheptylmethyl-, 1-cyclopropylethyl-,2-cyclopropylethyl-, 1-cyclobutylethyl-, 2-cyclobutylethyl-,1-cyclopentylethyl-, 2-cyclopentylethyl-, 1-cyclohexylethyl-,2-cyclohexylethyl-, 1-cycloheptylethyl-, 2-cycloheptylethyl-,3-cyclopropylpropyl-, 3-cyclobutylpropyl-, 3-cyclopentylpropyl-,3-cyclohexylpropyl-, 3-cycloheptylpropyl-. In one embodiment of theinvention, a (C₃-C₇)-cycloalkyl-substituted (C₁-C₆)-alkyl group is a(C₃-C₇)-cycloalkyl-(C₁-C₄)-alkyl-group, in another embodiment a(C₃-C₇)-cycloalkyl-(C₁-C₂)-alkyl- group, in another embodiment a(C₃-C₇)-cycloalkyl-CH₂— group. In the group cyclopropylmethyl-, andlikewise in all other groups containing one or two terminal hyphens likethe group alkyl-O—, for example, the terminal hyphens denote the freebonds via which the group is bonded to the adjacent moieties in themolecule, and thus indicates via which atoms or subgroups a groupcomposed of several atoms or subgroups is bonded.

In substituted phenyl groups, which can represent the group A and thegroup R³⁰, the substituents can be located in any positions. Inmonosubstituted phenyl groups, the substituent can be located inposition 2, in position 3 or in position 4. In disubstituted phenylgroups, the substituents can be located in positions 2 and 3, inpositions 2 and 4, in positions 2 and 5, in positions 2 and 6, inpositions 3 and 4, or in positions 3 and 5. In trisubstituted phenylgroups, the substituents can be located in positions 2, 3 and 4, inpositions 2, 3 and 5, in positions 2, 3 and 6, in positions 2, 4 and 5,in positions 2, 4 and 6, or in positions 3, 4 and 5. If a phenyl groupcarries four substituents, some of which can be fluorine atoms, forexample, the substituents can be located in positions 2, 3, 4 and 5, inpositions 2, 3, 4 and 6, or in positions 2, 3, 5 and 6. If apolysubstituted phenyl group, and in general any other polysubstitutedgroup, carries different substituents, each substituent can be locatedin any suitable position, and the present invention comprises allpositional isomers. The number of substituents in a substituted phenylgroup can be 1, 2, 3, 4 or 5. In one embodiment of the invention, thenumber of substituents in a substituted phenyl group, and likewise thenumber of substituents in any other substituted group which can carryone or more substituents, such as a heterocyclic group representing thegroup A, the group R³⁰ or the group Het, is 1, 2, 3 or 4, in anotherembodiment 1, 2 or 3, in another embodiment 1 or 2, in anotherembodiment 1, wherein the number of substituents in any occurrence ofsuch a substituted group is independent of the number of substituents inother occurrences.

In heterocyclic groups which can be present in the compounds of theformula I, including the group Het, aromatic heterocyclic groupsrepresenting the group A, heterocyclic groups representing the group R³⁰and heterocyclic rings formed by two groups R²¹ together with the carbonatoms carrying them, the hetero ring members can be present in anycombination and located in any suitable ring positions, provided thatthe resulting group and the compound of the formula I are suitable andsufficiently stable as a pharmaceutical active compound. In oneembodiment of the invention, two oxygen atoms in any heterocyclic ringin the compounds of the formula I cannot be present in adjacent ringpositions. In another embodiment of the invention, two hetero ringmembers selected from the series consisting of oxygen atoms and sulfuratoms or S(O)_(m) groups cannot be present in adjacent ring positions inany heterocyclic ring in the compounds of the formula I. In anotherembodiment of the invention, two hetero ring members selected from theseries consisting of oxygen atoms, sulfur atoms or S(O)_(m) groups, andnitrogen atoms carrying an exocyclic group like a hydrogen atom or asubstituent such as an alkyl group, cannot be present in adjacent ringpositions in any heterocyclic ring in the compounds of the formula I.The choice of hetero ring members in an aromatic heterocyclic ring islimited by the prerequisite that the ring is aromatic, i.e. it comprisesa cyclic system of six delocalized pi electrons in case of an aromaticmonocycle or 10 delocalized pi electrons in case of an aromatic bicycle.Monocyclic aromatic heterocycles are 5-membered or 6-membered rings and,in the case of a 5-membered ring, comprise one ring heteroatom selectedfrom the series consisting of oxygen, sulfur and nitrogen, wherein thisring nitrogen carries an exocyclic group like a hydrogen atom or asubstituent like an alkyl group, and optionally one or more further ringnitrogen atoms which do not carry an exocyclic group, and, in the caseof a 6-membered ring, comprise one or more nitrogen atoms as ringheteroatoms, but no oxygen atoms and sulfur atoms as ring heteroatoms.Heterocyclic groups in the compounds of the formula I can be bonded viaany suitable ring carbon atom and ring nitrogen atom, unless specifiedotherwise. In substituted heterocyclic groups, the substituents can belocated in any positions.

The number of ring heteroatoms which can be present in a heterocyclicgroup in the compounds of the formula I, the number of ring memberswhich can be present, and the degree of saturation, or hydrogenation,i.e. whether the heterocyclic group is saturated and does not contain adouble bond within the ring, or whether it is partially unsaturated butis not aromatic, or whether it is aromatic and thus contains two doublebonds within the ring in the case of a 5-membered monocyclic aromaticheterocycle, three double bonds within the ring in the case of a6-membered monocyclic aromatic heterocycle, and four or five doublebonds for in the case of bicyclic aromatic heterocycle comprising a6-membered ring and a 5-membered ring or two 6-membered rings, forexample, is specified in the definitions of the individual groups in thecompounds of the formula I. Examples of heterocyclic ring systems, fromwhich heterocyclic groups in the compounds of the formula I including,for example, the group Het, aromatic heterocyclic groups representingthe group A, heterocyclic groups representing the group R³⁰ andheterocyclic rings formed by two groups R²¹ together with the carbonatoms carrying them, can be derived, and from any one or more of whichany of the heterocyclic groups in the compounds of the formula I isselected in one embodiment of the invention, provided that the ringsystem is comprised by the definition of the respective group, areoxetane, thietane, azetidine, furan, tetrahydrofuran, thiophene,tetrahydrothiophene, pyrrole, pyrroline, pyrrolidine, [1,3]dioxole,[1,3]dioxolane, isoxazole ([1,2]oxazole), isoxazoline, isoxazolidine,oxazole ([1,3]oxazole), oxazoline, oxazolidine, isothiazole([1,2]thiazole), isothiazoline, isothiazolidine, thiazole([1,3]thiazole), thiazoline, thiazolidine, pyrazole, pyrazoline,pyrazolidine, imidazole, imidazoline, imidazolidine, [1,2,3]triazole,[1,2,4]triazole, [1,2,4]oxadiazole, [1,3,4]oxadiazole,[1,2,5]oxadiazole, [1,2,4]thiadiazole, pyran, tetrahydropyran,thiopyran, tetrahydrothiopyran, 2,3-dihydro[1,4]dioxine, [1,4]dioxane,pyridine, 1,2,5,6-tetrahydropyridine, piperidine, morpholine,thiomorpholine, piperazine, pyridazine, pyrimidine, pyrazine,[1,2,4]triazine, oxepane, thiepane, azepane, [1,3]diazepane,[1,4]diazepane, [1,4]oxazepane, [1,4]thiazepane, benzofuran,isobenzofuran, benzothiophene (benzo[b]thiophene), 1H-indole,2,3-dihydro-1H-indole, 2H-isoindole, benzo[1,3]dioxole, benzoxazole,benzthiazole, 1H-benzimidazole, chromane, isochromane, thiochromane,benzo[1,4]dioxane, 3,4-dihydro-2H-benzo[b][1,4]dioxepine(3,4-dihydro-2H-[1,5]benzodioxepine), 3,4-dihydro-2H-benzo[1,4]oxazine,3,4-dihydro-2H-benzo[1,4]thiazine, quinoline,5,6,7,8-tetrahydroquinoline, isoquinoline,5,6,7,8-tetrahydroisoquinoline, cinnoline, quinazoline, quinoxaline,phthalazine and [1,8]naphthyridine, which can all be unsubstituted orsubstituted in any suitable positions as specified in the definition ofthe respective group in the compounds of the formula I, wherein thegiven degree of unsaturation is by way of example only and in theindividual groups also ring systems with a higher or lower degree ofsaturation or unsaturation can be present in line with the definition ofthe group. Ring sulfur atoms, in particular in saturated and partiallyunsaturated heterocycles, can generally carry one or two oxo groups,i.e. doubly bonded oxygen atoms ((O), ═O), and in such heterocycles agroup S(O)_(m) be present as hetero ring member, in which the number mcan be 0 (zero) and thus a sulfur atom (—S—) be present in the ring, orm can be 1 and thus the group —S(O)—(—S(═O)—) be present in the ring, orm can be 2 and thus the group —S(O)₂—(—S(═O)₂—) be present in the ring.

As mentioned, unless specified otherwise, heterocyclic groups can bebonded via any suitable ring carbon atom and ring nitrogen atom, forexample in the case of heterocyclic groups representing R³⁰. In oneembodiment of the invention, any of the heterocyclic groups occurring inthe compounds of the formula I in any of its occurrences is,independently of its other occurrences and independently of any otherheterocyclic group, bonded via a ring carbon atom, and in anotherembodiment via a ring nitrogen atom, if applicable. Thus, for example,among others can an oxetane and a thietane ring be bonded via positions2 and 3, an azetidine ring via positions 1, 2 and 3, a furan ring, atetrahydrofuran ring, a thiophene ring and a tetrahydrothiophene ringvia positions 2 and 3, a pyrrole ring and a pyrrolidine ring viapositions 1, 2 and 3, an isoxazole ring and an isothiazole ring viapositions 3, 4 and 5, a pyrazole ring via positions 1, 3, 4 and 5, anoxazole ring and a thiazole ring via positions 2, 4 and 5, an imidazolering and an imidazolidine ring via positions 1, 2, 4 and 5, a[1,2,3]triazole ring via positions 1, 4 and 5, a [1,2,4]triazole ringvia positions 1, 3 and 5, a tetrahydropyran ring and atetrahydrothiopyran ring via positions 2, 3 and 4, a [1,4]dioxane ringvia position 2, a pyridine ring via positions 2, 3 and 4, a piperidinering via positions 1, 2, 3 and 4, a morpholine ring and a thiomorpholinering via positions 2, 3 and 4, a piperazine ring via positions 1 and 2,a pyrimidine ring via positions 2, 4 and 5, a pyrazine ring via position2, an azepane ring via positions 1, 2, 3 and 4, a benzofuran ring and abenzothiophene ring via positions 2, 3, 4, 5, 6 and 7, a 1H-indole ringand a 2,3-dihydro-1H-indole ring via positions 1, 2, 3, 4, 5, 6 and 7, abenzo[1,3]dioxole ring via positions 4, 5, 6 and 7, a benzoxazole ringand a benzthiazole ring via positions 2, 4, 5, 6 and 7, a1H-benzimidazole ring via positions 1, 2, 4, 5, 6 and 7, abenzo[1,4]dioxane ring via positions 5, 6, 7 and 8, a quinoline ring viapositions 2, 3, 4, 5, 6, 7 and 8, a 5,6,7,8-tetrahydroquinoline ring viapositions 2, 3 and 4, an isoquinoline ring via positions 1, 3, 4, 5, 6,7 and 8, a 5,6,7,8-tetrahydroisoquinoline ring via positions 1, 3 and 4,for example, wherein the resulting residues of the heterocyclic groupscan all be unsubstituted or substituted in any suitable positions asspecified in the definition of the respective group in the compounds ofthe formula I.

Halogen is fluorine, chlorine, bromine or iodine. In one embodiment ofthe invention, halogen is in any of its occurrences, independently ofany other occurrence, fluorine, chlorine or bromine, in anotherembodiment fluorine or chlorine, in another embodiment fluorine, inanother embodiment chlorine or bromine, in another embodiment chlorine,wherein all occurrences of halogen are independent of each other.

The present invention comprises all stereoisomeric forms of thecompounds of the formula I, for example all enantiomers anddiastereomers including cis/trans isomers. The invention likewisecomprises mixtures of two or more stereoisomeric forms, for examplemixtures of enantiomers and/or diastereomers including cis/transisomers, in all ratios. A subject of the present invention thus is acompound of the formula I, in any of its stereoisomeric forms or amixture of stereoisomeric forms in any ratio, or a pharmaceuticallyacceptable salt thereof. Asymmetric centers contained in the compoundsof the formula I can all independently of each other have Sconfiguration or R configuration. The invention relates to enantiomers,both the levorotatory and the dextrorotatory antipode, inenantiomerically pure form and essentially enantiomerically pure form,and in the form of their racemate, i.e. a mixture of the two enantiomersin molar ratio of 1:1, and in the form of mixtures of the twoenantiomers in all ratios. The invention likewise relates todiastereomers in the form of pure and essentially pure diastereomers andin the form of mixtures of two or more diastereomers in all ratios. Theinvention also comprises all cis/trans isomers of the compounds of theformula I in pure form and essentially pure form, and in the form ofmixtures of the cis isomer and the trans isomer in all ratios. Cis/transisomerism can occur in alkenyl groups and substituted rings. Thepreparation of individual stereoisomers, if desired, can be carried outby resolution of a mixture according to customary methods, for example,by chromatography or crystallization, or by use of stereochemicallyuniform starting compounds in the synthesis, or by stereoselectivereactions. Optionally, before a separation of stereoisomers aderivatization can be carried out. The separation of a mixture ofstereoisomers can be carried out at the stage of the compound of theformula I or at the stage of an intermediate in the course of thesynthesis. For example, in the case of a compound of the formula Icontaining an asymmetric center the individual enantiomers can beprepared by preparing the racemate of the compound of the formula I andresolving it into the enantiomers by high pressure liquid chromatographyon a chiral phase according to standard procedures, or resolving theracemate of any intermediate in the course of its synthesis by suchchromatography or by crystallization of a salt thereof with an opticallyactive amine or acid and converting the enantiomers of the intermediateinto the enantiomeric forms of the final compound of the formula I, orby performing an enantioselective reaction in the course of thesynthesis. The invention also comprises all tautomeric forms of thecompounds of the formula I, as well as all forms containing a specificisotopic pattern, for example deuterated compounds in which one or morehydrogen atoms are present in form of the deuterium isotop.

Besides the free compounds of the formula I, i.e. the compounds of theformula I themselves in which any acidic and basic groups are notpresent in the form of a salt and which may also be termed “salt-free”compounds, the present invention comprises also salts of the compoundsof the formula I, in particular their physiologically acceptable salts,or toxicologically acceptable salts, or pharmaceutically acceptablesalts, which can be formed on one or more acidic groups, for example oncarboxylic acid groups, or basic groups, for example amino group orbasic heterocyclic moieties, in the compounds of the formula I. Thecompounds of the formula I may thus be deprotonated on an acidic groupby an inorganic or organic base and used, for example, in the form ofthe alkali metal salts. Compounds of the formula I comprising at leastone basic group may be prepared and used in the form of their acidaddition salts, for example in the form of pharmaceutically acceptablesalts with inorganic acids and organic acids, such as salts withhydrochloric acid and thus be present in the form of the hydrochlorides,for example. Salts can in general be prepared from acidic and basiccompounds of the formula I by reaction with an acid or base in a solventor diluent according to customary procedures. If the compounds of theformula I simultaneously contain an acidic and a basic group in themolecule, the invention also includes internal salts (betaines,zwitterions) in addition to the salt forms mentioned. The presentinvention also comprises all salts of the compounds of the formula Iwhich, because of low physiological tolerability, are not directlysuitable for use as a pharmaceutical, but are suitable as intermediatesfor chemical reactions or for the preparation of physiologicallyacceptable salts, for example by means of anion exchange or cationexchange.

In one embodiment of the invention an aromatic heterocyclic grouprepresenting the divalent group A is a monocyclic 5-membered or6-membered group or a bicyclic 8-membered to 10-membered group, inanother embodiment a monocyclic 5-membered or 6-membered group or abicyclic 9-membered or 10-membered group. In one embodiment an aromaticheterocyclic group representing the group A is a monocyclic 5-memberedor 6-membered group, in another embodiment it is a monocyclic 5-memberedgroup, in another embodiment it is a monocyclic 6-membered group, inanother embodiment it is a bicyclic 9-membered or 10-membered group, inanother embodiment it is a bicyclic 9-membered group, and in anotherembodiment it is a bicyclic 10-membered group. In one embodiment thenumber of hetero ring members in a heterocycle representing A is 1, inanother embodiment it is 2. In one embodiment the hetero ring members ina heterocycle representing A are selected from the series consisting ofN, N(R²⁰) and S, in another embodiment from the series consisting of N,N(R²⁰) and O, in another embodiment from the series consisting of N andN(R²⁰), in another embodiment from the series consisting of N and S, inanother embodiment from the series consisting of N and O, in anotherembodiment they are N, and in another embodiment they are S. In the caseof the group A, the hetero ring member N denotes a ring nitrogen atomwhich is bonded to the adjacent ring atoms in A via a single bond and adouble bond and via which the ring A cannot be bonded to an anothermoiety in the molecule, as well as a ring nitrogen atom which is bondedto the adjacent ring atoms in A via two single bonds and which has afree valence via which the ring A can be bonded to the moiety G-E-.Examples of heterocycles, from which an aromatic heterocyclic grouprepresenting A can be derived and from any one or more of which anaromatic heterocyclic group representing A is selected in one embodimentof the invention, are furan, thiophene, pyrrole, isoxazole, oxazole,isothiazole, thiazole, pyrazole, imidazole, pyridine, pyridazine,pyrimidine, pyrazine, benzofuran, benzothiophene, 1H-indole,benzoxazole, benzthiazole, 1H-benzimidazole, 1H-indazole,1H-pyrrolo[2,3-b]pyridine, pyrazolo[1,5-a]pyridine, quinoline,isoquinoline, cinnoline, quinazoline, quinoxaline, which can all beunsubstituted or substituted on ring carbon atoms by one or moreidentical or different substituents R²¹. In another embodiment, anaromatic heterocyclic group representing A is derived from an aromaticheterocyclic group selected from the series consisting of thiophene,thiazole, pyrazole, imidazole, pyridine and pyrimidine, in anotherembodiment from the series consisting of thiophene, thiazole, pyrazoleand pyridine, in another embodiment from the series consisting ofthiophene, thiazole and pyridine, in another embodiment from the seriesconsisting of thiophene, thiazole and pyrazole, in another embodimentfrom the series consisting of thiophene and pyridine, in anotherembodiment from the series consisting of thiazole and pyridine, inanother embodiment from the series consisting of pyrazole and pyridine,in another from the series consisting of thiazole and pyrazole, inanother embodiment an aromatic heterocyclic group representing A isderived from thiophene, in another embodiment from thiazole, in anotherembodiment from pyrazole, in another embodiment from pyridine, inanother embodiment from pyrimidine, which can all be unsubstituted orsubstituted on ring carbon atoms by one or more identical or differentsubstituents R²¹. In one embodiment A is an aromatic heterocyclic group,which is unsubstituted or substituted on ring carbon atoms by one ormore identical of different substituents R²¹, in another embodiment A isphenyl, which is unsubstituted or substituted by one or more identicalof different substituents R²¹. Also a group A that is unsubstituted,i.e. that does not carry any substituents R²¹, of course carries thegroup G-E-depicted in formula I, in which G and E can have all theirmeanings. As specified in the general definition of the group A, thedivalent group A is bonded to the 9H-pyrido[3,4-b]indole ring depictedin formula I via a ring carbon atom. The group E, and the group G incase the group E is a direct bond, can be bonded to a ring carbon atomin the group A or to a ring nitrogen atom, i.e. to a hetero ring memberN, in the group A.

If the divalent group E is a direct bond, the group G is linked to thegroup A via a single bond. If the group E is a chain, it consists of 1,2, 3, 4 or 5 chain members which are defined as specified in thedefinition of E, to the terminal chain members of which, or to the solechain member of which in case the chain consists of 1 chain member only,the groups G and A are bonded. In one embodiment of the invention thedivalent group E is a direct bond. In another embodiment, the divalentgroup E is a chain consisting of 1, 2, 3, 4 or 5 chain members which aredefined as specified in the definition of E. In one embodiment, thenumber of chain members in a chain E is 1, 2, 3 or 4, in anotherembodiment 2, 3, 4 or 5, in another embodiment 1, 2 or 3, in anotherembodiment 2, 3 or 4, in another embodiment 2 or 3, in anotherembodiment 1, in another embodiment 2, in another embodiment 3, inanother embodiment 4. In one embodiment, 0 (zero) or 1 chain members ina chain E are identical or different hetero chain members selected fromthe series consisting of N(R²⁵), O and S(O)_(m), in another embodiment 1or 2 chain members are such hetero chain members, in another embodiment0 chain member is such a hetero chain member, in another embodiment 1chain member is such a hetero chain member, and in another embodiment 2chain members are such heterochain members. If 2 hetero chain membersare present in a chain E, in one embodiment they are not present inadjacent positions of the chain, i. e., in this embodiment they areseparated by at least 1 chain member C(R²⁶)(R²⁷), in another embodimentthey are not present in adjacent positions of the chain unless one ofthem is the group S(O)_(m) in which m is 1 or 2, and in anotherembodiment they are separated by 2 or 3, in another embodiment by 2, inanother embodiment by 3, chain members C(R²⁶)(R²⁷). In one embodiment,hetero chain members in a chain E are selected from the seriesconsisting of N(R²⁵) and O, in another embodiment from the seriesconsisting of O and S(O)_(m), in another embodiment they are identicalor different groups N(R²⁵), in another embodiment they are O, i.e.oxygen atoms, and in another embodiment they are identical or differentgroups S(O)_(m). In one embodiment the number m in the hetero chainmember S(O)_(m) in a chain E is selected from the series consisting of 0and 1, in another embodiment from the series consisting of 1 and 2, inanother embodiment from the series consisting of 0 and 2, in anotherembodiment it is 0, in another embodiment it is 1, and in anotherembodiment it is 2. If the terminal chain member in a chain E that isbonded to the group A, or the sole chain member in case the chainconsists of 1 chain member only, is bonded to a ring nitrogen atom in A,in one embodiment such terminal chain member or sole chain member is nota hetero chain member, and in another embodiment such terminal chainmember or sole chain member is not a hetero chain number selected fromthe series consisting of N(R²⁵), O and S(O)_(m) in which the number m is0. If the terminal chain member in a chain E that is bonded to the groupG, or the sole chain member in case the chain consists of 1 chain memberonly, is bonded to a ring nitrogen atom in a ring R³⁰ representing G ofto halogen atom or a cyano group representing G, in one embodiment suchterminal chain member is not a hetero chain member, and in anotherembodiment such terminal chain member is not a hetero chain numberselected from the series consisting of N(R²⁵), O and S(O)_(m) in whichthe number m is 0.

In one embodiment of the invention the divalent group E is chosen from adirect bond and from any one or more of the chains which are present inthe following examples of groups G-E-, which groups are bonded to thegroup A depicted in formula I by the free bond represented by theterminal hyphen, and from which groups the divalent chains E themselvesare obtained by removing the group G, wherein in these groups the groupsR²⁵, R²⁶ and R²⁷ and the number m are defined as specified above orbelow:

-   G-C(R²⁶)(R²⁷)—,-   G-C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—,-   G-C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—,-   G-C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—,-   G-O—,-   G-C(R²⁶)(R²⁷)—O—,-   G-C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—O—,-   G-C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—O—,-   G-O—C(R²⁶)(R²⁷)—,-   G-O—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—,-   G-O—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—,-   G-C(R²⁶)(R²⁷)—O—C(R²⁶)(R²⁷)—,-   G-C(R²⁶)(R²⁷)—O—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—,-   G-C(R²⁶)(R²⁷)—O—C(R²⁶)(R²⁷)—,-   G-C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—O—C(R²⁶)(R²⁷)—,-   G-O—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—O—,-   G-O—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—O—,-   G-S(O)_(m)—,-   G-C(R²⁶)(R²⁷)—S(O)_(m)—,-   G-C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—S(O)_(m)—,-   G-S(O)_(m)—C(R²⁶)(R²⁷)—,-   G-S(O)_(m)—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—,-   G-N(R²⁵)—,-   G-C(R²⁶)(R²⁷)—N(R²⁵)—,-   G-C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—N(R²⁵)—,-   G-N(R²⁵)—C(R²⁶)(R²⁷)—,-   G-N(R²⁵)—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—,-   G-N(R²⁵)—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—,-   G-N(R²⁵)—C(R²⁶)(R²⁷)—N(R²⁵)—,-   G-N(R²⁵)—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—N(R²⁵)—,-   G-N(R²⁵)—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—N(R²⁵)—C(R²⁶)(R²⁷)—,-   G-N(R²⁵)—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—O—,-   G-N(R²⁵)—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—O—,-   G-O—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—N(R²⁵)—,-   G-O—C(R²⁶)(R²⁷)—C(R²⁶)(R²⁷)—N(R²⁵)—C(R²⁶)(R²⁷)—,-   G-S(O)₂—N(R²⁵)—.

In one embodiment of the invention the group G is selected from theseries consisting of hydrogen, halogen, (C₁-C₄)-alkyl and R³⁰, inanother embodiment from the series consisting of hydrogen, (C₁-C₄)-alkyland R³⁰, in another embodiment from the series consisting of hydrogen,halogen and R³⁰, in another embodiment from the series consisting ofhydrogen and R³⁰, in another embodiment from the series consisting ofhydrogen, halogen and (C₁-C₄)-alkyl, in another embodiment from theseries consisting of of hydrogen, halogen, (C₁-C₄)-alkyl and cyano, inanother embodiment G is hydrogen, and in another embodiment G is R³⁰.

In one embodiment of the invention any one or more of the groups R¹, R³,R⁴ and R⁶ are independently of each other selected from the seriesconsisting of hydrogen, halogen and (C₁-C₂)-alkyl, in another embodimentfrom the series consisting of hydrogen, halogen and C₁-alkyl, in anotherembodiment from the series consisting of hydrogen and halogen, inanother embodiment from the series consisting of hydrogen and(C₁-C₄)-alkyl, in another embodiment from the series consisting ofhydrogen and (C₁-C₂)-alkyl, in another embodiment from the seriesconsisting of hydrogen and C₁-alkyl, and in another embodiment they areindependently of each other hydrogen, in another embodiment halogen, inanother embodiment (C₁-C₄)-alkyl, in another embodiment (C₁-C₂)-alkyland in another embodiment C₁-alkyl.

In one embodiment of the invention the group R² is selected from theseries consisting of hydrogen, halogen, (C₁-C₂)-alkyl and(C₁-C₂)-alkyl-O—C(O)—, in another embodiment from the series consistingof hydrogen, halogen, C₁-alkyl and (C₁-C₂)-alkyl-O—C(O)—, in anotherembodiment from the series consisting of hydrogen, halogen and(C₁-C₄)-alkyl, in another embodiment from the series consisting ofhydrogen, halogen and (C₁-C₂)-alkyl, in another embodiment from theseries consisting of hydrogen, halogen and C₁-alkyl, in anotherembodiment from the series consisting of hydrogen and halogen, inanother embodiment from the series consisting of hydrogen and(C₁-C₄)-alkyl, in another embodiment from the series consisting ofhydrogen and (C₁-C₂)-alkyl, in another embodiment from the seriesconsisting of hydrogen and C₁-alkyl, and in another embodiment R² ishydrogen.

In one embodiment of the invention the group R⁵ is selected from theseries consisting of hydrogen, halogen, (C₁-C₄)-alkyl, (C₁-C₄)-alkyl-O—and cyano, in another embodiment from the series consisting of hydrogen,halogen, (C₁-C₄)-alkyl, cyano, R⁷—O—C(O)— and R⁸—N(R⁹)—C(O)—, in anotherembodiment from the series consisting of hydrogen, halogen,(C₁-C₄)-alkyl and cyano, in another embodiment from the seriesconsisting of hydrogen, halogen and (C₁-C₄)-alkyl, in another embodimentfrom the series consisting hydrogen and halogen, in another embodimentfrom the series consisting of halogen and (C₁-C₄)-alkyl, and in anotherembodiment R⁵ is halogen. In one embodiment halogen representing R⁵ isselected from the series consisting of chlorine and bromine, in anotherembodiment it is chlorine, and in another embodiment it is bromine. Inone embodiment a (C₁-C₄)-alkyl group representing R⁵ or present in R⁵ isindependently of any other such alkyl group a (C₁-C₂)-alkyl group, inanother embodiment a C₁-alkyl group.

In one embodiment of the invention any one or more of the groups R⁷, R⁸,R⁹, R²⁰, R²², R²⁵, R³¹, R³³, R³⁴ and R⁴⁰ are independently of each otherselected from the series consisting of hydrogen and (C₁-C₂)-alkyl, inanother embodiment from the series consisting of hydrogen and C₁-alkyl,and in another embodiment they are independently of each other hydrogen,in another embodiment (C₁-C₄)-alkyl, in another embodiment(C₁-C₂)-alkyl, in another embodiment C₁-alkyl.

In one embodiment of the invention R¹⁹ is selected from the seriesconsisting of hydrogen, (C₁-C₆)-alkyl, (C₂-C₆)-alkenyl and(C₂-C₆)-alkynyl, in another embodiment from the series consisting ofhydrogen, (C₁-C₆)-alkyl, (C₂-C₆)-alkynyl and (C₃-C₇)-cycloalkyl, inanother embodiment from the series consisting of hydrogen, (C₁-C₆)-alkyland (C₂-C₆)-alkynyl, in another embodiment from the series consisting ofhydrogen, (C₁-C₆)-alkyl and (C₃-C₇)-cycloalkyl, in another embodimentfrom the series consisting of hydrogen and (C₁-C₆)-alkyl, in anotherembodiment from the series consisting of (C₁-C₆)-alkyl, (C₂-C₆)-alkenyl,(C₂-C₆)-alkynyl and (C₃-C₇)-cycloalkyl, in another embodiment from theseries consisting of (C₁-C₆)-alkyl, (C₂-C₆)-alkenyl and (C₂-C₆)-alkynyl,in another embodiment from the series consisting of (C₁-C₆)-alkyl,(C₂-C₆)-alkynyl and (C₃-C₇)-cycloalkyl, in another embodiment from theseries consisting of (C₁-C₆)-alkyl and (C₂-C₆)-alkynyl, in anotherembodiment from the series consisting of (C₁-C₆)-alkyl and(C₃-C₇)-cycloalkyl, in another embodiment R¹⁰ is (C₁-C₆)-alkyl, whereinin all these embodiments (C₁-C₆)-alkyl is unsubstituted or substitutedby 1 or 2 identical or different substituents selected from the seriesconsisting of (C₃-C₇)-cycloalkyl, Het, cyano and (C₁-C₄)-alkyl-O—. Inone embodiment R¹⁰ is hydrogen. In one embodiment a (C₁-C₆)-alkyl grouprepresenting R¹⁰ is (C₁-C₄)-alkyl, in another embodiment (C₁-C₃)-alkyl,in another embodiment (C₁-C₂)-alkyl, in another embodiment C₁-alkyl. Inone embodiment a (C₁-C₆)-alkyl group representing R¹⁰ is unsubstitutedor substituted by 1 substituent selected from the series consisting of(C₃-C₇)-cycloalkyl, Het, cyano and (C₁-C₄)-alkyl-O—. In one embodimentthe substituents in a substituted alkyl group representing R¹⁰ areselected from the series consisting of (C₃-C₇)-cycloalkyl, Het andcyano, in another embodiment from the series consisting of(C₃-C₇)-cycloalkyl, Het and (C₁-C₄)-alkyl-O—, in another embodiment fromthe series consisting of (C₃-C₇)-cycloalkyl and Het, and in anotherembodiment substituents in a substituted alkyl group representing R¹⁰are (C₃-C₇)-cycloalkyl groups, and in another embodiment substituents ina substituted alkyl group representing R¹⁰ are groups Het. As statedabove and applies to alkyl groups in general, besides the substituentsspecified in the definition of the group R¹⁰ the alkyl grouprepresenting R¹⁰ can also carry one or more fluorine substituents.Cycloalkyl groups representing R¹⁰ or present in R¹⁰ can beunsubstituted or substituted by one or more identical or differentsubstituents selected from the series consisting of fluorine and(C₁-C₄)-alkyl.

If two groups R²¹ bonded to adjacent ring carbon atoms in the group Atogether with the ring carbon atoms carrying them form a 5-membered to7-membered ring, this ring is mono-unsaturated. I.e., the resulting ringcontains one double bond within the ring, which double bond is presentbetween the said two adjacent ring carbon in the aromatic ring A thatare common to the ring A and the ring formed by the two groups R²¹, andbecause of the rules of nomenclature for fused rings this double bond isregarded as a double bond present in either of the two fused rings. Iftwo substituents R²¹ together with the ring carbon atoms in A carryingthem form a ring, further substituents R²¹ selected from the seriesconsisting of halogen, (C₁-C₄)-alkyl, (C₁-C₄)-alkyl-O— and cyano canadditionally be present in the group A. The case that two groups R²¹bonded to adjacent ring carbon atoms in A together with the carbon atomscarrying them form a 5-membered to 7-membered ring, can in other termsbe regarded as two groups R²¹ together forming a divalent residuecomprising a chain of 3 to 5 members, of which 0, 1 or 2 are identicalor different heteroatom moieties selected from the series consisting ofN(R²²), O and S(O)_(m), the terminal atoms of which are bonded to thetwo adjacent ring carbon atoms in the group A. Examples of such divalentresidues, from any one or more of which two groups R²¹ bonded toadjacent ring carbon atoms in A are selected in one embodiment of theinvention, are the residues —CH₂—CH₂—CH₂—, —CH₂—CH₂—CH₂—CH₂—,—CH₂—CH₂—CH₂—CH₂—CH₂—, —O—CH₂—CH₂—, —CH₂—CH₂—O—, —O—CH₂—CH₂—CH₂—,—CH₂—CH₂—CH₂—O—, —O—CH₂—O—, —O—CH₂—CH₂—O—, —O—CH₂—CH₂—CH₂—O—,—N(R²²)—CH₂—CH₂—O—, —O—CH₂—CH₂—N(R²²)—, —S(O)_(m)—CH₂—CH₂—N(R²²)— and—N(R²²)—CH₂—CH₂—S(O)_(m)—, which can all be substituted on carbon atomsby one or more identical or different substituents selected from theseries consisting of fluorine and (C₁-C₄)-alkyl, and can thus also bepresent, for example, as the residues —O—CF₂—O—, —O—C(CH₃)₂—O—,—O—CH(CH₃)—CH₂—, —CH(CH₃)—CH₂—O—, —O—C(CH₃)₂—CH₂—, —C(CH₃)₂—CH₂—O—. Inone embodiment, the hetero ring members which are optionally present ina ring formed by two groups R²¹ bonded to adjacent ring carbon atoms inAr together with the carbon atoms carrying them, are selected from theseries consisting of N(R²²) and O, in another embodiment from the seriesconsisting of O and S(O)_(m), and in another embodiment they are O(oxygen atoms). In one embodiment, the ring which can be formed by twogroups R²¹ bonded to adjacent ring carbon atoms in A together with thering carbon atoms carrying them, is a 5-membered or 6-membered ring, inanother embodiment a 5-membered ring, in another embodiment a 6-memberedring. In one embodiment, the ring which can be formed by two groups R²¹bonded to adjacent carbon atoms in A together with the carbon atomscarrying them, comprises 0 ring heteroatoms, i.e. it is a carbocyclicring, and in another embodiment it comprises 1 or 2 identical ordifferent hetero ring members. In one embodiment, the number ofsubstituents selected from the series consisting of fluorine and(C₁-C₄)-alkyl on a ring formed by two groups R²¹ together with thecarbon atoms carrying them, is 1, 2, 3 or 4, in another embodiment 1, 2or 3, in another embodiment 1 or 2, in another embodiment 1, and inanother embodiment it is 0.

In one embodiment of the invention R²¹ is selected from the seriesconsisting of halogen, (C₁-C₄)-alkyl and (C₁-C₄)-alkyl-O—, in anotherembodiment from the series consisting of halogen, (C₁-C₄)-alkyl andcyano, in another embodiment from the series consisting of halogen and(C₁-C₄)-alkyl, and in another embodiment they are halogen, and in allthese embodiments two groups R²¹ bonded to adjacent ring carbon atoms inA, together with the carbon atoms carrying them, can form a 5-memberedto 7-membered mono-unsaturated ring, which comprises 0, 1 or 2 identicalor different hetero ring members selected from the series consisting ofN(R²²), O and S(O)_(m) and which is unsubstituted or substituted on ringcarbon atoms by one or more identical or different substituents selectedfrom the series consisting of fluorine and (C₁-C₄)-alkyl.

In one embodiment of the invention R²¹ is selected from the seriesconsisting of halogen, (C₁-C₄)-alkyl, (C₁-C₄)-alkyl-O— and cyano, inanother embodiment from the series consisting of halogen, (C₁-C₄)-alkyland (C₁-C₄)-alkyl-O—, in another embodiment from the series consistingof halogen, (C₁-C₄)-alkyl and cyano, in another embodiment from theseries consisting of halogen and (C₁-C₄)-alkyl, and in anotherembodiment they are halogen, and in all these embodiments two groups R²¹bonded to adjacent ring carbon atoms in A, together with the carbonatoms carrying them, do not form a 5-membered to 7-memberedmono-unsaturated ring.

In one embodiment a (C₁-C₄)-alkyl group representing R²¹ or present in a(C₁-C₄)-alkyl-O— group representing R²¹ is independently of any othersuch alkyl group a (C₁-C₃)-alkyl group, in another embodiment a(C₁-C₂)-alkyl group, in another embodiment a C₁-alkyl group. In oneembodiment halogen representing R²¹ is selected from the seriesconsisting of fluorine, chlorine and bromine, in another embodiment fromthe series consisting fluorine and chlorine, in another embodiment it isfluorine, and in another embodiment it is chlorine.

If in a group C(R²⁶)(R²⁷) in a chain E the groups R²⁶ and R²⁷ bonded tothe same carbon atom together are oxo, i.e. an oxygen atom bonded via adouble bond ((O), ═O), they together with the carbon atom carrying themform a divalent carbonyl group (—C(O)—, —(C═O)—). If adjacent to such acarbonyl group a hetero chain member such as N(R²⁵) or O, for example,is present in a chain E, or if such a carbonyl group is bonded to a ringnitrogen in the group A or in the group R³⁰ representing the group G, acarboxylic acid amide moiety, a carboxylic acid ester moiety or acarboxylic acid moiety results. In one embodiment of the invention inone group C(R²⁶)(R²⁷) in a chain E the groups R²⁶ and R²⁷ bonded to thesame carbon atom together can be oxo, in another embodiment in nonegroup C(R²⁶)(R²⁷) in a chain E the groups R²⁶ and R²⁷ bonded to the samecarbon atom together are oxo.

In one embodiment of the invention R²⁶ and R²⁷ are independently of eachother selected from the series consisting of hydrogen, fluorine and(C₁-C₄)-alkyl, in another embodiment from the series consisting ofhydrogen, (C₁-C₄)-alkyl and hydroxy, in another embodiment from theseries consisting of hydrogen and (C₁-C₄)-alkyl, in another embodimentfrom the series consisting of hydrogen and fluorine, and in anotherembodiment they are hydrogen, and in all these embodiments in one or twogroups C(R²⁶)(R²⁷) in a chain E the groups R²⁶ and R²⁷ bonded to thesame carbon atom together can be oxo.

In one embodiment R²⁶ and R²⁷ are independently of each other selectedfrom the series consisting of hydrogen, fluorine, (C₁-C₄)-alkyl andhydroxy, in another embodiment from the series consisting of hydrogen,fluorine and (C₁-C₄)-alkyl, in another embodiment from the seriesconsisting of hydrogen, (C₁-C₄)-alkyl and hydroxy, in another embodimentfrom the series consisting of hydrogen and (C₁-C₄)-alkyl, in anotherembodiment from the series consisting of hydrogen and fluorine, and inanother embodiment they are hydrogen, and in all these embodiments innone of the groups C(R²⁶)(R²⁷) in a chain E the groups R²⁶ and R²⁷bonded to the same carbon atom together are oxo.

In one embodiment a (C₁-C₄)-alkyl group representing R²⁶ or R²⁷ isindependently of any other such alkyl group a (C₁-C₃)-alkyl group, inanother embodiment a (C₁-C₂)-alkyl group, in another embodiment aC₁-alkyl group.

The group R³⁰ representing the group G is a residue of a monocyclic andbicyclic ring containing 3, 4, 5, 6, 7, 8, 9 or 10 ring members. In oneembodiment of the invention, the number of ring members in a monocyclicgroup R³⁰ is 3, 4, 5, 6 or 7, in another embodiment 3, 4, 5 or 6, inanother embodiment 3 or 4, in another embodiment 4, 5 or 6, in anotherembodiment 5, 6 or 7, in another embodiment 5 or 6, in anotherembodiment 3, in another embodiment 4, in another embodiment 5, inanother embodiment 6, and the number of ring members in a bicyclic groupR³⁰ is 6, 7, 8, 9 or 10, in another embodiment 7, 8, 9 or 10, in anotherembodiment 8, 9 or 10, in another embodiment 9, and in anotherembodiment 10. In one embodiment, the number of ring members of thecyclic group R³⁰ is from 3 to 10 in the case of a carbocyclic ring, andfrom 4 to 10 in the case of a heterocyclic ring. In one embodiment, thecyclic group R³⁰ is monocyclic, in another embodiment it is bicyclic. Abicyclic group R³⁰ can be a fused ring system or a bridged ring systemor a spirocyclic ring system. In one embodiment, a bicyclic group R³⁰ isa fused or bridged ring system, in another embodiment it is a fused ringsystem.

An unsaturated group representing R³⁰ can be aromatic, i.e. it containstwo double bonds within the ring in the case of a 5-membered monocyclicaromatic heterocycle which double bonds, together with an electron pairon a ring heteroatom, form a delocalized cyclic system of six pielectrons, and three double bonds within the ring in the case of aphenyl group or a 6-membered monocyclic aromatic heterocycle, or two,three, four or five double bonds within two fused rings in the case of abicyclic group comprising one or two aromatic rings, or it can bepartially unsaturated, i.e., it contains one or more, for example one ortwo, double bonds within the ring via which it is bonded, but is notaromatic within this ring. In one embodiment of the invention the cyclicgroup R³⁰ is a saturated group, in another embodiment it is anunsaturated group including partially unsaturated groups and aromaticgroups. In another embodiment R³⁰ is a saturated group or a partiallyunsaturated group, in another embodiment it is a saturated group or anaromatic group, in another embodiment it is a saturated group, and inanother embodiment it is an aromatic group.

The cyclic group R³⁰ can be a carbocyclic group, i.e. comprise 0 (zero)hetero ring members, or a heterocyclic group, i.e. comprise 1, 2 or 3identical or different hetero ring members selected from the seriesconsisting of N, N(R³¹), O and S(O)_(m). In the case of the group R³⁰,the hetero ring member N denotes a ring nitrogen atom which is bonded tothe adjacent ring atoms via two single bonds and which has a freevalence via which the ring R³⁰ is bonded to the group E, as occurs in apyrrole ring, pyrazole ring, piperidine ring or morpholine ring, forexample, as well as a ring nitrogen atom which is bonded to the adjacentring atoms via a single bond and a double bond or via three single bondsand via which the ring R³⁰ cannot be bonded to the group E, unlessquaternization is present, as occurs in a pyridine ring, thiazole ring,quinoline ring or 1-azabicyclo[2.2.2]octane ring, for example. In oneembodiment, R³⁰ comprises 0, 1 or 2 identical or different hetero ringmembers, in another embodiment 0 or 1 hetero ring member, and in anotherembodiment R³⁰ comprises 0 hetero ring member and thus is a carbocyclicgroup. In another embodiment R³⁰ is a heterocyclic group which comprises1, 2 or 3 identical or different hetero ring members, in anotherembodiment 1 or 2 identical or different hetero ring members, in anotherembodiment 1 hetero ring members. In one embodiment, the hetero ringmembers in R³⁰ are selected from the series consisting of N, N(R³¹) andO, in another embodiment from the series consisting of N, N(R³¹) andS(O)_(m), in another embodiment from the series consisting of N, O andS(O)_(m), in another embodiment from the series consisting of N andN(R³¹), in another embodiment from the series consisting of N and O, inanother embodiment from the series consisting of N(R³¹) and O, inanother embodiment they are N, in another embodiment they are N(R³¹),and in another embodiment they are O. In one embodiment two hetero ringmembers in a group R³⁰ can only be present in adjacent ring positions ifone them is S(O)_(m) in which m is 1 or 2, or if one of them is N whichis bonded to the two adjacent ring atoms via a single bond and a doublebond and does not have a free valence via which the ring R³⁰ is bondedto the group E. In the latter embodiment, two oxygen atoms, for example,can thus not be present in adjacent ring positions in R³⁰. Heterocyclicgroups R³⁰ can be bonded to the group E via a ring nitrogen atom, i.e. ahetero ring member N, or a ring carbon atom. In one embodiment aheterocyclic group R³⁰ is bonded via a ring carbon atom, in anotherembodiment it is bonded via a ring nitrogen atom, i.e. a hetero ringmember N.

Examples of carbocyclic groups, which can represent R³⁰ and any one ormore of which may be included in the definition of R³⁰ in oneembodiment, and from any one or more of which R³⁰ is selected in anotherembodiment, are cycloalkyl groups such as (C₃-C₇)-cycloalkyl includingcyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl,cycloalkenyl groups such as (C₅-C₇)-cycloalkenyl includingcyclopentenyl, cyclohexenyl and cycloheptenyl, bicycloalkyl groups suchas (C₆-C₁₀)-bicycloalkyl, phenyl groups, indanyl groups includingindan-1-yl and indan-2-yl, and naphthalenyl (naphthyl) groups includingnaphthalen-1-yl and naphthalen-2-yl, for example, which can all beunsubstituted or substituted by one or more identical or differentsubstituents R³². The explanations given above, for example with respectto cycloalkyl groups, for example their optional substitution byfluorine substituents and (C₁-C₄)-alkyl substituents, and with respectto phenyl groups apply accordingly to such groups representing R³⁰.

Examples of heterocyclic groups, which can represent R³⁰ and any one ormore of which may be included in the definition of R³⁰ in oneembodiment, and from any one or more of which R³⁰ is selected in anotherembodiment, are oxetanyl including oxetan-2-yl and oxetan-3-yl,tetrahydrofuranyl including tetrahydrofuran-2-yl andtetrahydrofuran-3-yl, tetrahydropyranyl including tetrahydropyran-2-yl,tetrahydropyran-3-yl and tetrahydropyran-4-yl, oxepanyl includingoxepan-2-yl, oxepan-3-yl and oxepan-4-yl, tetrahydrothiophene includingtetrahydrothiophen-2-yl and tetrahydrothiophen-3-yl,tetrahydrothiopyranyl including tetrahydrothiopyran-2-yl,tetrahydrothiopyran-3-yl and tetrahydrothiopyran-4-yl, azetidinylincluding azetidin-1-yl, azetidin-2-yl and azetidin-3-yl, pyrrolidinylincluding pyrrolidin-1-yl, pyrrolidin-2-yl and pyrrolidin-3-yl,piperidinyl including piperidin-1-yl, piperidin-2-yl, piperidin-3-yl andpiperidin-4-yl, 1,2-dihydropyridinyl including 1,2-dihydropyridin-1-yl,1,2-dihydropyridin-2-yl, 1,2-dihydropyridin-3-yl,1,2-dihydropyridin-4-yl, 1,2-dihydropyridin-5-yl and1,2-dihydropyridin-6-yl, 1,2,3,6-tetrahydropyridinyl including1,2,3,6-tetrahydropyridin-1-yl, 1,2,3,6-tetrahydropyridin-2-yl,1,2,3,6-tetrahydropyridin-3-yl, 1,2,3,6-tetrahydropyridin-4-yl,1,2,3,6-tetrahydropyridin-5-yl and 1,2,3,6-tetrahydropyridin-6-yl,azepanyl including azepan-1-yl, azepan-2-yl, azepan-3-yl andazepan-4-yl, 1-azabicyclo[2.2.2]octanyl including1-azabicyclo[2.2.2]octan-2-yl, 1-azabicyclo[2.2.2]octan-3-yl and1-azabicyclo[2.2.2]octan-4-yl, [1,3]dioxolanyl including[1,3]dioxolan-2-yl and [1,3]dioxolan-4-yl, [1,4]dioxanyl including[1,4]dioxan-2-yl, [1,3]oxazolidinyl including [1,3]oxazolidin-2-yl,[1,3]oxazolidin-3-yl, [1,3]oxazolidin-4-yl and [1,3]oxazolidin-5-yl,[1,3]thiazolidinyl including [1,3]thiazolidin-2-yl,[1,3]thiazolidin-3-yl, [1,3]thiazolidin-4-yl and [1,3]thiazolidin-5-yl,imidazolidinyl including imidazolidin-1-yl, imidazolidin-2-yl,imidazolidin-4-yl, morpholinyl including morpholin-2-yl, morpholin-3-yland morpholin-4-yl, thiomorpholinyl including thiomorpholin-2-yl,thiomorpholin-3-yl and thiomorpholin-4-yl, piperazinyl includingpiperazin-1-yl and piperazin-2-yl, furanyl including furan-2-yl andfuran-3-yl, thiophenyl (thienyl) including thiophen-2-yl andthiophen-3-yl, pyrrolyl including pyrrol-1-yl, pyrrol-2-yl andpyrrol-3-yl, isoxazolyl including isoxazol-3-yl, isoxazol-4-yl andisoxazol-5-yl, oxazolyl including oxazol-2-yl, oxazol-4-yl andoxazol-5-yl, thiazolyl including thiazol-2-yl, thiazol-4-yl andthiazol-5-yl, pyrazolyl including pyrazol-1-yl, pyrazol-3-yl,pyrazol-4-yl and pyrazol-5-yl, imidazolyl including imidazolyl-1-yl,imidazol-2-yl, imidazol-4-yl and imidazol-5-yl, [1,2,4]triazolylincluding [1,2,4]triazol-1-yl, [1,2,4]triazol-3-yl and[1,2,4]triazol-5-yl, pyridinyl (pyridyl) including pyridin-2-yl,pyridin-3-yl and pyridin-4-yl, pyridazinyl including pyridazin-3-yl andpyridazin-4-yl, pyrimidinyl including pyrimidin-2-yl, pyrimidin-4-yl andpyrimidiny-5-yl, pyrazinyl including pyrazin-2-yl, indolyl includingindol-1-yl, indol-2-yl, indol-3-yl, indol-4-yl, indol-5-yl, indol-6-yland indol-7-yl, benzimidazolyl including benzimidazol-1-yl,benzimidazol-2-yl, benzimidazol-4-yl, benzimidazol-5-yl,benzimidazol-6-yl and benzimidazol-7-yl, quinolinyl includingquinolin-2-yl, quinolin-3-yl, quinolin-4-yl, quinolin-5-yl,quinolin-6-yl, quinolin-7-yl and quinolin-8-yl, isoquinolinyl includingquinolin-1-yl, quinolin-3-yl, quinolin-4-yl, quinolin-5-yl,quinolin-6-yl, quinolin-7-yl and quinolin-8-yl,2,3-dihydrobenzo[1,4]dioxinyl including2,3-dihydrobenzo[1,4]dioxin-2-yl, 2,3-dihydrobenzo[1,4]dioxin-5-yl and2,3-dihydrobenzo[1,4]dioxin-6-yl, quinazolinyl includingquinazolin-2-yl, quinazolin-4-yl, quinazolin-5-yl, quinazolin-6-yl,quinazolin-7-yl and quinazolin-8-yl, which can all be unsubstituted orsubstituted on ring carbon atoms by one or more identical or differentsubstituents R³² and, if applicable, which can all carry on ringnitrogen atoms capable of carrying a substituent a (C₁-C₄)-alkylsubstituent corresponding to the denotation (C₁-C₄)-alkyl of the groupR³¹ occurring in the hetero ring member N(R³¹) in R³⁰, and can carry onall ring sulfur atoms capable of carrying oxygen atoms one or two oxygenatoms corresponding to the oxygen atoms in the hetero ring memberS(O)_(m) in R³⁰.

In one embodiment of the invention, the number of substituents R³² whichcan be present on carbon atoms in R³⁰, is 1, 2, 3, 4, 5 or 6, in anotherembodiment it is 1, 2, 3, 4 or 5, in another embodiment it is 1, 2, 3 or4, in another embodiment it is 1, 2 or 3, in another embodiment it is 1or 2, in another embodiment it is 1. In one embodiment, R³⁰ isunsubstituted.

In one embodiment of the invention the group R³² is selected from theseries consisting of halogen, (C₁-C₄)-alkyl, hydroxy, oxo,(C₁-C₄)-alkyl-O—, R³³—N(R³⁴)— and Het, in another embodiment from theseries consisting of halogen, (C₁-C₄)-alkyl, (C₁-C₄)-alkyl-O—,R³³—N(R³⁴)— and Het, in another embodiment from the series consisting ofhalogen, (C₁-C₄)-alkyl, hydroxy, oxo, (C₁-C₄)-alkyl-O— and R³³—N(R³⁴)—,in another embodiment from the series consisting of halogen,(C₁-C₄)-alkyl, hydroxy, oxo and (C₁-C₄)-alkyl-O—, in another embodimentfrom the series consisting of halogen, (C₁-C₄)-alkyl, oxo and(C₁-C₄)-alkyl-O—, in another embodiment from the series consisting ofhalogen, (C₁-C₄)-alkyl and (C₁-C₄)-alkyl-O—, in another embodiment fromthe series consisting of halogen and (C₁-C₄)-alkyl, in anotherembodiment they are halogen, and in another embodiment they are(C₁-C₄)-alkyl. In one embodiment a (C₁-C₄)-alkyl group representing R³²or present in a (C₁-C₄)-alkyl-O— group representing R³² is independentlyof any other such alkyl group a (C₁-C₃)-alkyl group, in anotherembodiment a (C₁-C₂)-alkyl group, in another embodiment a C₁-alkylgroup. In one embodiment halogen representing R³² is selected from theseries consisting of fluorine, chlorine and bromine, in anotherembodiment from the series consisting fluorine and chlorine, in anotherembodiment it is fluorine, in another embodiment it is chlorine, and inanother embodiment it is bromine.

The group Het contains 4, 5, 6 or 7 ring members. In one embodiment ofthe invention, Het is 4-membered to 6-membered, in another embodiment4-membered or 5-membered, in another embodiment 5-membered or6-membered, in another embodiment 4-membered, in another embodiment5-membered, in another embodiment 6-membered. In one embodiment, Hetcomprises 1 hetero ring member. In one embodiment, the hetero ringmembers in Het are selected from the series consisting of N, N(R⁴⁰) andO, in another embodiment from the series consisting of N and N(R⁴⁰), inanother embodiment from the series consisting of O and S(O)_(m), inanother embodiment they are O. In one embodiment two hetero ring membersin a group Het can only be present in adjacent ring positions if onethem is S(O)_(m) in which m is 1 or 2, in another embodiment two heteroring members in a group Het are not present in adjacent ring positions.In the latter embodiment two oxygen atoms, for example, can thus not bepresent in adjacent ring positions. The group Het can be bonded via aring nitrogen atom, i.e. a hetero ring member N, or a ring carbon atom.In one embodiment Het is bonded via a ring carbon atom, in anotherembodiment it is bonded via a ring nitrogen atom, i.e. a hetero ringmember N. In the case of the group Het the hetero ring member N denotesa ring nitrogen atom which is bonded to the adjacent ring atoms in Hetvia two single bonds and which has a free valence via which the ring Hetis bonded to another moiety in the molecule, as occurs in the case of apyrrolidine ring, piperidine ring or morpholine ring, for example.Examples of heterocyclic groups, from any one or more of which Het ischosen in one embodiment, are oxetanyl, tetrahydrofuranyl,tetrahydropyranyl, oxepanyl, tetrahydrothiophenyl,tetrahydrothiopyranyl, azetidinyl, pyrrolidinyl, piperidinyl, azepanyl,morpholinyl, thiomorpholinyl and piperazinyl, including the morespecific groups in which the binding position is specified and which arelisted above in the section relating to the group R³⁰. In oneembodiment, the number of optional substituents on ring carbon atoms ina group Het is 1, 2, 3 or 4, in another embodiment it is 1, 2 or 3, inanother embodiment it is 1 or 2, in another embodiment it is 1. In oneembodiment Het is unsubstituted. In one embodiment, substituents on ringcarbon atoms in Het are (C₁-C₄)-alkyl group, in another embodiment(C₁-C₃)-alkyl groups, in another embodiment (C₁-C₂)-alkyl groups, inanother embodiment C₁-alkyl groups.

In one embodiment of the invention the number m, which is an integer, isin any of its occurrences, independently of any other occurrence,selected from the numbers 0 and 2, in another embodiment 1 and 2, inanother embodiment it is 0, in another embodiment it is 1 and in anotherembodiment it is 2.

A subject of the invention are all compounds of the formula I whereinany one or more structural elements such as groups, residues,substituents and numbers are defined as in any of the specifiedembodiments or definitions of the elements, or have one or more of thespecific meanings which are mentioned herein as examples of elements,wherein all combinations of one or more definitions of compounds orelements and/or specified embodiments and/or specific meanings ofelements are a subject of the present invention. Also with respect toall such compounds of the formula I, all their stereoisomeric forms andmixtures of stereoisomeric forms in any ratio, and theirpharmaceutically acceptable salts are a subject of the presentinvention.

As an example of compounds of the invention, which with respect to anystructural elements are defined as in specified embodiments of theinvention or definitions of such elements, compounds of the formula Imay be mentioned, wherein

A is phenyl, which is unsubstituted or substituted on ring carbon atomsby one or more identical of different substituents R²¹;

E is a direct bond;

G is selected from the series consisting of hydrogen, halogen,(C₁-C₄)-alkyl and cyano;

and all other groups and numbers are defined as in the generaldefinition of the compounds of the formula I or in any specifiedembodiments of the invention or definitions of structural elements, andthe pharmaceutically acceptable salts thereof.

As another such example compounds of the formula I may be mentioned,wherein

A is phenyl, which is unsubstituted or substituted on ring carbon atomsby one or more identical of different substituents R²¹;

E is a direct bond;

G is R³⁰;

and all other groups and numbers are defined as in the generaldefinition of the compounds of the formula I or in any specifiedembodiments of the invention or definitions of structural elements, andthe pharmaceutically acceptable salts thereof.

As another such example compounds of the formula I may be mentioned,wherein A is phenyl, which is unsubstituted or substituted on ringcarbon atoms by one or more identical of different substituents R²¹;

E is a chain consisting of 1 to 5 chain members of which 0, 1 or 2 chainmembers are identical or different hetero chain members selected fromthe series consisting of N(R²⁵), O and S(O)_(m), and the other chainmembers are identical or different groups C(R²⁶)(R²⁷);

G is selected from the series consisting of hydrogen, halogen,(C₁-C₄)-alkyl and cyano;

and all other groups and numbers are defined as in the generaldefinition of the compounds of the formula I or in any specifiedembodiments of the invention or definitions of structural elements, andthe pharmaceutically acceptable salts thereof.

As another such example compounds of the formula I may be mentioned,wherein; A is phenyl, which is unsubstituted or substituted on ringcarbon atoms by one or more identical of different substituents R²¹;

E is a chain consisting of 1 to 5 chain members of which 0, 1 or 2 chainmembers are identical or different hetero chain members selected fromthe series consisting of N(R²⁵), O and S(O)_(m) and the other chainmembers are identical or different groups C(R²⁶)(R²⁷);

G is R³⁰;

and all other groups and numbers are defined as in the generaldefinition of the compounds of the formula I or in any specifiedembodiments of the invention or definitions of structural elements, andthe pharmaceutically acceptable salts thereof.

As another such example compounds of the formula I may be mentioned,wherein A is a monocyclic or bicyclic, 5-membered to 10-membered,aromatic heterocyclic group, which comprises 1 or 2 identical ordifferent hetero ring members selected from the series consisting of N,N(R²⁰), O and S and is bonded via a ring carbon atom, and which isunsubstituted or substituted on ring carbon atoms by one or moreidentical of different substituents R²¹;

E is a direct bond;

G is selected from the series consisting of hydrogen, halogen,(C₁-C₄)-alkyl and cyano;

and all other groups and numbers are defined as in the generaldefinition of the compounds of the formula I or in any specifiedembodiments of the invention or definitions of structural elements, andthe pharmaceutically acceptable salts thereof.

As another such example compounds of the formula I may be mentioned,wherein A is a monocyclic or bicyclic, 5-membered to 10-membered,aromatic heterocyclic group, which comprises 1 or 2 identical ordifferent hetero ring members selected from the series consisting of N,N(R²⁰), O and S and is bonded via a ring carbon atom, and which isunsubstituted or substituted on ring carbon atoms by one or moreidentical of different substituents R²¹;

E is a direct bond;

G is R³⁰;

and all other groups and numbers are defined as in the generaldefinition of the compounds of the formula I or in any specifiedembodiments of the invention or definitions of structural elements, andthe pharmaceutically acceptable salts thereof.

As another such example compounds of the formula I may be mentioned,wherein A is a monocyclic or bicyclic, 5-membered to 10-membered,aromatic heterocyclic group, which comprises 1 or 2 identical ordifferent hetero ring members selected from the series consisting of N,N(R²⁰), O and S and is bonded via a ring carbon atom, and which isunsubstituted or substituted on ring carbon atoms by one or moreidentical of different substituents R²¹;

E is a chain consisting of 1 to 5 chain members of which 0, 1 or 2 chainmembers are identical or different hetero chain members selected fromthe series consisting of N(R²⁵), O and S(O)_(m), and the other chainmembers are identical or different groups C(R²⁶)(R²⁷);

G is selected from the series consisting of hydrogen, halogen,(C₁-C₄)-alkyl and cyano;

and all other groups and numbers are defined as in the generaldefinition of the compounds of the formula I or in any specifiedembodiments of the invention or definitions of structural elements, andthe pharmaceutically acceptable salts thereof.

As another such example compounds of the formula I may be mentioned,wherein; A is a monocyclic or bicyclic, 5-membered to 10-membered,aromatic heterocyclic group, which comprises 1 or 2 identical ordifferent hetero ring members selected from the series consisting of N,N(R²⁰), O and S and is bonded via a ring carbon atom, and which isunsubstituted or substituted on ring carbon atoms by one or moreidentical of different substituents R²¹;

E is a chain consisting of 1 to 5 chain members of which 0, 1 or 2 chainmembers are identical or different hetero chain members selected fromthe series consisting of N(R²⁵), O and S(O)_(m), and the other chainmembers are identical or different groups C(R²⁶)(R²⁷);

G is R³⁰;

and all other groups and numbers are defined as in the generaldefinition of the compounds of the formula I or in any specifiedembodiments of the invention or definitions of structural elements, andthe pharmaceutically acceptable salts thereof.

As another such example, compounds of the formula I may be mentioned,wherein

A is selected from the series consisting of phenyl and a monocyclic,5-membered or 6-membered, aromatic heterocyclic group, which comprises 1or 2 identical or different hetero ring members selected from the seriesconsisting of N, N(R²⁰), 0 and S and is bonded via a ring carbon atom,wherein phenyl and the heterocyclic group are unsubstituted orsubstituted on ring carbon atoms by one or more identical of differentsubstituents R²¹;

E is a direct bond or a chain consisting of 1 to 4 chain members ofwhich 0, 1 or 2 chain members are identical or different hetero chainmembers selected from the series consisting of N(R²⁵), O and S(O)_(m),and the other chain members are identical or different groupsC(R²⁶)(R²⁷);

G is selected from the series consisting of hydrogen, halogen,(C₁-C₄)-alkyl and R³⁰;

R¹, R³, R⁴ and R⁶ are independently of each other selected from theseries consisting of hydrogen, halogen and (C₁-C₃)-alkyl;

R² is selected from the series consisting of hydrogen, halogen and(C₁-C₃)-alkyl;

R⁵ is selected from the series consisting of hydrogen, halogen,(C₁-C₄)-alkyl, (C₁-C₄)-alkyl-O— and cyano;

R¹⁰ is selected from the series consisting of hydrogen, (C₁-C₆)-alkyland (C₃-C₇)-cycloalkyl, wherein alkyl is unsubstituted or substituted by1 substituent selected from the series consisting of (C₃-C₇)-cycloalkyl,Het, cyano and (C₁-C₄)-alkyl-O—, and wherein all cycloalkyl groups areunsubstituted or substituted by one or more identical or differentsubstituents selected from the series consisting of fluorine and(C₁-C₄)-alkyl;

R²⁰, R²², R²⁵, R³¹ and R⁴⁰ are independently of each other selected fromthe series consisting of hydrogen and (C₁-C₄)-alkyl;

R²¹ is selected from the series consisting of halogen, (C₁-C₄)-alkyl,(C₁-C₄)-alkyl-O— and cyano, and two groups R²¹ bonded to adjacent ringcarbon atoms in the group A, together with the carbon atoms carryingthem, can form a 5-membered or 6-membered mono-unsaturated ring, whichcomprises 0, 1 or 2 identical or different hetero ring members selectedfrom the series consisting of N(R²²), O and S(O)_(m) and which isunsubstituted or substituted on ring carbon atoms by one or moreidentical or different substituents selected from the series consistingof fluorine and (C₁-C₄)-alkyl;

R²⁶ and R²⁷ are independently of each other selected from the seriesconsisting of hydrogen, fluorine, (C₁-C₃)-alkyl and hydroxy, and in onegroup C(R²⁶)(R²⁷) the groups R²⁶ and R²⁷ bonded to the same carbon atomtogether can be oxo;

R³⁰ is a monocyclic or bicyclic, 3-membered to 10-membered ring, whichis saturated or unsaturated and comprises 0, 1, 2 or 3 identical ordifferent hetero ring members selected from the series consisting of N,N(R³¹), O and S(O)_(m), and which is unsubstituted or substituted onring carbon atoms by one or more identical or different substituentsR³²;

R³² is selected from the series consisting of halogen, (C₁-C₄)-alkyl,hydroxy, oxo, (C₁-C₄)-alkyl-O— and cyano;

Het is a monocyclic, 4-membered to 6-membered, saturated heterocyclicgroup, which comprises 1 or 2 identical or different hetero ring membersselected from the series consisting of N, N(R⁴⁰) and O, and which isunsubstituted or substituted on ring carbon atoms by one or moreidentical or different substituents selected from the series consistingof fluorine and (C₁-C₄)-alkyl;

m is selected from the series consisting of 0, 1 and 2, wherein allnumbers m are independent of each other and can be identical ordifferent;

wherein all alkyl groups, independently of any other substituents whichcan be present on an alkyl group, can be substituted by one or morefluorine substituents;

and the pharmaceutically acceptable salts thereof.

As another such example, compounds of the formula I may be mentioned,wherein

A is selected from the series consisting of phenyl and a monocyclic,5-membered or 6-membered, aromatic heterocyclic group, which comprises 1or 2 identical or different hetero ring members selected from the seriesconsisting of N, N(R²⁰), 0 and

S and is bonded via a ring carbon atom, wherein phenyl and theheterocyclic group are unsubstituted or substituted on ring carbon atomsby one or more identical of different substituents R²¹;

E is a direct bond or a chain consisting of 1 to 4 chain members ofwhich 0, 1 or 2 chain members are identical or different hetero chainmembers selected from the series consisting of N(R²⁵) and O, and theother chain members are identical or different groups C(R²⁶)(R²⁷);

G is selected from the series consisting of hydrogen, (C₁-C₄)-alkyl andR³⁰;

R¹ and R⁴ are independently of each other selected from the seriesconsisting of hydrogen, halogen and (C₁-C₃)-alkyl;

R² is selected from the series consisting of hydrogen, halogen and(C₁-C₃)-alkyl;

R³ and R⁶ are independently of each other selected from the seriesconsisting of hydrogen, halogen and C₁-alkyl;

R⁵ is selected from the series consisting of hydrogen, halogen,(C₁-C₄)-alkyl and cyano;

R¹⁰ is selected from the series consisting of hydrogen, (C₁-C₆)-alkyland (C₃-C₇)-cycloalkyl, wherein alkyl is unsubstituted or substituted by1 substituent selected from the series consisting of (C₃-C₇)-cycloalkyl,Het, cyano and (C₁-C₄)-alkyl-O—, and wherein all cycloalkyl groups areunsubstituted or substituted by one or more identical or differentsubstituents selected from the series consisting of fluorine and(C₁-C₄)-alkyl;

R²⁰, R²², R²⁵, R³¹ and R⁴⁰ are independently of each other selected fromthe series consisting of hydrogen and (C₁-C₄)-alkyl;

R²¹ is selected from the series consisting of halogen, (C₁-C₄)-alkyl,(C₁-C₄)-alkyl-O— and cyano, and two groups R²¹ bonded to adjacent ringcarbon atoms in the group A, together with the carbon atoms carryingthem, can form a 5-membered or 6-membered mono-unsaturated ring, whichcomprises 0, 1 or 2 identical or different hetero ring members selectedfrom the series consisting of N(R²²) and O, and which is unsubstitutedor substituted on ring carbon atoms by one or more identical ordifferent substituents selected from the series consisting of fluorineand O₁-alkyl;

R²⁶ and R²⁷ are independently of each other selected from the seriesconsisting of hydrogen, fluorine, (C₁-C₃)-alkyl and hydroxy, and in onegroup C(R²⁶)(R²⁷) the groups R²⁶ and R²⁷ bonded to the same carbon atomtogether can be oxo;

R³⁰ is a monocyclic or bicyclic, 3-membered to 10-membered ring, whichis saturated or aromatic and comprises 0, 1 or 2 identical or differenthetero ring members selected from the series consisting of N, N(R³¹), Oand S(O)_(m), and which is unsubstituted or substituted on ring carbonatoms by one or more identical or different substituents R³²;

R³² is selected from the series consisting of halogen, (C₁-C₄)-alkyl,hydroxy, oxo and (C₁-C₄)-alkyl-O—; Het is a monocyclic, 4-membered to6-membered, saturated heterocyclic group, which comprises 1 hetero ringmember selected from the series consisting of N(R⁴⁰) and O, and which isunsubstituted or substituted on ring carbon atoms by one or moreidentical or different substituents selected from the series consistingof fluorine and (C₁-C₃)-alkyl;

m is selected from the series consisting of 0, 1 and 2, wherein allnumbers m are independent of each other and can be identical ordifferent;

wherein all alkyl groups, independently of any other substituents whichcan be present on an alkyl group, can be substituted by one or morefluorine substituents;

and the pharmaceutically acceptable salts thereof.

As another such example, compounds of the formula I may be mentioned,wherein

A is selected from the series consisting of phenyl and a monocyclic,5-membered or 6-membered, aromatic heterocyclic group, which comprises 1or 2 identical or different hetero ring members selected from the seriesconsisting of N, N(R²⁰) and S and is bonded via a ring carbon atom,wherein phenyl and the heterocyclic group are unsubstituted orsubstituted on ring carbon atoms by one or more identical of differentsubstituents R²¹;

E is a direct bond or a chain consisting of 1 to 4 chain members ofwhich 0 or 1 chain members are identical or different hetero chainmembers selected from the series consisting of N(R²⁵) and O, and theother chain members are identical or different groups C(R²⁶)(R²⁷);

G is selected from the series consisting of hydrogen and R³⁰;

R¹ and R⁴ are independently of each other selected from the seriesconsisting of hydrogen, halogen and (C₁-C₂)-alkyl;

R² is selected from the series consisting of hydrogen, halogen and(C₁-C₂)-alkyl;

R³ and R⁶ are independently of each other selected from the seriesconsisting of hydrogen, halogen and C₁-alkyl;

R⁵ is selected from the series consisting of hydrogen, halogen and(C₁-C₂)-alkyl;

R¹⁰ is selected from the series consisting of hydrogen, (C₁-C₄)-alkyland (C₃-C₅)-cycloalkyl, wherein alkyl is unsubstituted or substituted by1 substituent selected from the series consisting of (C₃-C₅)cycloalkyland Het, and wherein all cycloalkyl groups are unsubstituted orsubstituted by one or more identical or different substituents(C₁-C₂)-alkyl;

R²⁰, R²⁵ and R³¹ are independently of each other selected from theseries consisting of hydrogen and (C₁-C₃)-alkyl;

R²¹ is selected from the series consisting of halogen, (C₁-C₄)-alkyl,(C₁-C₄)-alkyl-O— and cyano;

R²⁶ and R²⁷ are independently of each other selected from the seriesconsisting of hydrogen, fluorine, C₁-alkyl and hydroxy, and in one groupC(R²⁶)(R²⁷) the groups R²⁶ and R²⁷ bonded to the same carbon atomtogether can be oxo;

R³⁰ is a monocyclic 3-membered to 6-membered or bicyclic 9-membered to10-membered ring, which is saturated or aromatic and comprises 0, 1 or 2identical or different hetero ring members selected from the seriesconsisting of N, N(R³¹) and O, and which is unsubstituted or substitutedon ring carbon atoms by one or more identical or different substituentsR³²;

R³² is selected from the series consisting of halogen, (C₁-C₃)-alkyl,hydroxy and oxo;

Het is a monocyclic, 4-membered or 5-membered, saturated heterocyclicgroup, which comprises 1 hetero ring member which is O, and which isunsubstituted or substituted on ring carbon atoms by one or moreidentical or different substituents (C₁-C₃)-alkyl;

wherein all alkyl groups, independently of any other substituents whichcan be present on an alkyl group, can be substituted by one or morefluorine substituents;

and the pharmaceutically acceptable salts thereof.

As another such example, compounds of the formula I may be mentioned,wherein

A is selected from the series consisting of phenyl and the aromaticheterocyclic groups pyrazolyl and pyridinyl, wherein phenyl and theheterocyclic groups are unsubstituted or substituted on ring carbonatoms by one or more identical of different substituents R²¹;

E is a direct bond or a chain consisting of 1 to 3 chain members ofwhich 0 or 1 chain member is a hetero chain member which is O, and theother chain members are identical or different groups C(R²⁶)(R²⁷);

G is selected from the series consisting of hydrogen and R³⁰;

R¹ and R⁴ are independently of each other selected from the seriesconsisting of hydrogen, halogen and C₁-alkyl;

R² is selected from the series consisting of hydrogen, halogen andC₁-alkyl; R³ and R⁶ are hydrogen; R⁵ is selected from the seriesconsisting of halogen and (C₁-C₂)-alkyl;

R¹⁰ is selected from the series consisting of hydrogen, (C₁-C₄)-alkyland (C₃-C₅)-cycloalkyl, wherein alkyl is unsubstituted or substituted by1 substituent selected from the series consisting of (C₃-C₅)cycloalkyland Het;

R²¹ is selected from the series consisting of halogen, (C₁-C₄)-alkyl,(C₁-C₄)-alkyl-O— and cyano;

R²⁶ and R²⁷ are independently of each other selected from the seriesconsisting of hydrogen, fluorine and C₁-alkyl;

R³⁰ is a monocyclic, 3-membered to 6-membered ring, which is saturatedor aromatic and comprises 0, 1 or 2 identical or different hetero ringmembers selected from the series consisting of N, N(R³¹) and O, andwhich is unsubstituted or substituted on ring carbon atoms by one ormore identical or different substituents R³²;

R³¹ is selected from the series consisting of hydrogen and(C₁-C₃)-alkyl;

R³² is selected from the series consisting of halogen and (C₁-C₃)-alkyl;

Het is a monocyclic, 4-membered or 5-membered, saturated heterocyclicgroup, which comprises 1 hetero ring member which is O, and which isunsubstituted or substituted on ring carbon atoms by one or moreidentical or different substituents (C₁-C₃)-alkyl;

wherein all alkyl groups, independently of any other substituents whichcan be present on an alkyl group, can be substituted by one or morefluorine substituents;

and the pharmaceutically acceptable salts thereof.

A subject of the invention also is a compound of the formula I which isselected from any of the specific compounds of the formula I which aredisclosed herein, or is any one of the specific compounds of the formulaI which are disclosed herein, irrespective thereof whether they aredisclosed as a free compound and/or as a specific salt, or apharmaceutically acceptable salt thereof, wherein the compound of theformula I is a subject of the invention in any of its stereoisomericforms or a mixture of stereoisomeric forms in any ratio, if applicable.For example, a subject of the invention is a compound of the formula Iwhich is selected from the series consisting of:

-   6-Bromo-9-ethyl-1-methyl-8-(1-pyridin-3-ylmethyl-1H-pyrazol-4-yl)-9H-pyrido[3,4-b]indole,-   6-Chloro-1,5-dimethyl-8-[4-(3-methyl-oxetan-3-ylmethoxy)-phenyl]-9H-pyrido[3,4-b]indole,-   2-(4-[6-Chloro-9-(2,2,2-trifluoroethyl)-9H-pyrido[3,4-b]indol-8-yl]pyrazol-1-yl)ethanol,-   6-Chloro-1-methyl-8-[4-(2-pyrazol-1-ylethoxy)-phenyl]-9H-pyrido[3,4-b]indole,-   6-Bromo-9-ethyl-1,3-dimethyl-8-(1-methyl-1H-pyrazol-4-yl)-9H-pyrido[3,4-b]indole,-   6-Chloro-8-(4-methoxy-phenyl)-1,9-dimethyl-9H-pyrido[3,4-b]indole,-   6-Chloro-8-(4-methoxy-phenyl)-1,5-dimethyl-9H-pyrido[3,4-b]indole,-   8-(4-Methoxy-phenyl)-1-methyl-9H-pyrido[3,4-b]indole-6-carbonitrile,-   6-Chloro-1-methyl-8-[4-(1-methyl-1H-imidazol-2-ylmethoxy)-phenyl]-9H-pyrido[3,4-b]indole,-   6-Chloro-1,5-dimethyl-8-[4-(2-pyrazol-1-yl-ethoxy)-phenyl]-9H-pyrido[3,4-b]pyridine,-   6-Chloro-9-cyclopropylmethyl-8-(2,6-dichloro-pyridin-3-yl)-9H-pyrido[3,4-b]indole,-   6-Chloro-8-(2,6-dichloro-pyridin-3-yl)-9-ethyl-9H-pyrido[3,4-b]indole,-   8-(2,6-Dichloro-pyridin-3-yl)-1,6-dimethyl-9H-pyrido[3,4-b]indole,-   6-Chloro-9-ethyl-1-methyl-8-(1-pyridin-3-ylmethyl-1H-pyrazol-4-yl)-9H-pyrido[3,4-b]indole,-   6-Chloro-8-(4-chloro-phenyl)-9-ethyl-1-methyl-9H-pyrido[3,4-b]indole,-   6-Chloro-8-(4-methoxy-phenyl)-1-methyl-9H-pyrido[3,4-b]indole,-   6-Chloro-8-chroman-6-yl-1-methyl-9H-pyrido[3,4-b]indole,-   6-Chloro-8-[4-(2-imidazol-1-yl-ethoxy)-phenyl]-1-methyl-9H-pyrido[3,4-b]indole,-   6-Bromo-9-ethyl-1-methyl-8-(1-methyl-1H-pyrazol-4-yl)-9H-pyrido[3,4-b]indole,-   4-(6-Chloro-1-methyl-9H-pyrido[3,4-b]indol-8-yl)-pyridin-2-ylamine,-   6-Chloro-1-methyl-8-[4-(1-methyl-pyrrolidin-3-ylmethoxy)-phenyl]-9H-pyrido[3,4-b]indole,-   6-Chloro-9-ethyl-1-methyl-8-[4-(3-methyl-oxetan-3-ylmethoxy)-phenyl]-9H-pyrido[3,4-b]indole,-   6-Bromo-9-ethyl-1-methyl-8-[4-(3-methyl-oxetan-3-ylmethoxy)-phenyl]-9H-pyrido[3,4-b]indole,    and-   6-Chloro-9-cyclopropylmethyl-8-(1-pyridin-3-ylmethyl-1H-pyrazol-4-yl)-9H-pyrido[3,4-b]indole,    or which is any one of these compounds, and its pharmaceutically    acceptable salts.

Another subject of the present invention are processes for thepreparation of the compounds of the formula I which are outlined belowand by which the compounds of the formula I and intermediates occurringin the course of their synthesis, and salts thereof, are obtainable. Thecompounds of the formula I can in general be prepared by usingprocedures and techniques which per se are known to a person skilled inthe art. In one of the processes a compound of the formula I isprepared, for example, by cross-coupling of a compound of the formula IIwith an organoboron compound of the formula III under the conditions ofthe well-known Suzuki reaction, also known as Suzuki-Miyauracross-coupling reaction, or another Suzuki-type reaction ormodifications thereof, in the presence of a transition metal catalyst.The reaction is reviewed in F. Alonso et al., Tetrahedron 2008, 64,3047-3101, for example.

The groups R¹ to R⁶ and R¹⁰ in the compound of the formula II and thegroups A, E and G in the compound of the formula III are defined as inthe compound of the formula I, and in addition functional groups can bepresent in protected form or in the form of a precursor group, which issubsequently converted into the final group. The group X in the compoundof the formula II is suitable leaving group, such as halogen selectedfrom the series consisting of chlorine, bromine and iodine, in oneembodiment of the invention from the series consisting of bromine andiodine, or a sulfonyloxy group like trifluoromethanesulfonyloxy(CF₃—SO₂—O—), for example.

The groups Y in the compound of the formula III are hydrogen, and inthis case the compound of the formula III thus is a boronic acid, or(C₁-C₄)-alkyl, in one embodiment of the invention (C₁-C₃)-alkyl likemethyl, ethyl or isopropyl, and in this case the compound of the formulaIII is a boronic acid alkyl ester, or the two groups Y, together withthe —O—B—O— moiety to which they are bonded, form a saturated 5-memberedor 6-membered ring, which comprises 2 or 3 carbon atoms as ring atoms inaddition to the —O—B—O— moiety and is unsubstituted or substituted byone or more (C₁-C₄)-alkyl substituents, for example methyl substituents,and in this case the compound of the formula III is a cyclic boronicacid alkyl ester. In the latter case the ring formed by the two groupsY, together with the —O—B—O— moiety to which they are bonded, is a1,3,2-dioxaborolane ring or 1,3,2-dioxaborinane ring, which areunsubstituted or substituted by one or more (C₁-C₄)-alkyl substituents,for example a 4,4,5,5-tetramethyl-1,3,2-dioxaborolane ring as present inthe pinacol ester (2,3-dimethyl-2,3-butanediol ester) of the respectiveboronic acid, or a 5,5-dimethyl-1,3,2-dioxaborinane ring as present inthe neopentyl glycol ester (2,2-dimethyl-1,3-propanediol ester) of therespective boronic acid. In one embodiment of the invention the compoundof the formula III is a boronic acid or a cyclic boronic acid alkylester as specified afore. In another embodiment the compound of theformula III is a boronic acid or a boronic acid pinacol ester, i.e., thegroups Y are hydrogen or, together with the —O—B—O— moiety to which theyare bonded, form a 4,4,5,5-tetramethyl-1,3,2-dioxaborolane ring.Alternatively, instead of with a compound of the formula III, a compoundof the formula II can be reacted with an organotrifluoroborate salt,such as a potassium organotrifluoroborate, i.e. a compound of theformula G-E-A-BF₃ ⁻K⁺ in which the groups A, E and G are defined as inthe compound of the formula I and in addition functional groups can bepresent in protected form or in the form of a precursor group, whichsalts can be obtained from boronic acids and fluorides such as potassiumhydrogen difluoride and are reviewed in S. Darses et al., Chem. Rev.2008, 108, 288-325, for example.

The reaction of the compounds of the formula II with the compounds ofthe formula III is generally performed in an inert solvent, such as ahydrocarbon like benzene or toluene, an ether like 1,2-dimethoxyethane(DME), tetrahydrofuran (THF) or dioxane, an amide like dimethylformamide(DMF), an alcohol like ethanol or isobutanol, a nitrile likeacetonitrile, or water, or a mixture of such solvents, for example intoluene or in a mixture of 1,2-dimethoxyethane and water in a ratio offrom about 5:1 to about 2:1 by volume, for example in a ratio of about3:1 by volume. The reaction is generally performed at elevatedtemperatures, such as at temperatures from about 50° C. to about 150°C., for example at temperatures from about 90° C. to about 130° C., in aheated flask or vessel or in a microwave vessel heated in a microwaveirradiation device (cf. V. P. Metha et al., Chem. Soc. Rev. 2011, 40,4925-4936). The reaction time generally is from about 5 minutes to about24 hours, for example from about 10 minutes to about 10 hours, dependingon the particulars of the specific case such as the reactivity of thereactants and the chosen temperature.

As transition metal catalyst in Suzuki reactions and similarcross-coupling reactions commonly palladium compounds are employed, butother metal catalysts such as nickel catalysts can also be used (cf.F.-S. Han, Chem. Soc. Rev. 2013, 42, 5270-5298, for example). Examplesof palladium compounds which can be employed as catalysts in thereaction of the compounds of the formula II with the compounds of theformula III, are palladium(II) salts like palladium(II) diacetate orpalladium(II) dichloride, which can also be employed in the presence ofa phosphine such as 1,1′-bis(diphenylphosphino)ferrocene,tricyclohexylphosphine or triphenylphosphine, and palladium complexeslike tetrakis(triphenylphosphine)palladium(0),bis(tri-tert-butylphosphine)palladium(0),bis(triphenylphosphine)palladium(II) dichloride,bis(tri-tert-butylphosphine)palladium(II) dichloride,1,1′-bis(diphenylphosphino)ferrocene-palladium(II) dichloride which isabbreviated herein as “BDFP” and which is commonly employed in the formof a complex with dichloromethane, orbis(dibenzylideneacetone)palladium(0) in the presence oftri-tert-butylphosphine.

Palladium catalysts on solid supports like iron oxide, magnesium oxide,magnesium lanthanum oxide, apatite or anionic clay materials as well aspolymer-supported palladium catalysts can also be used. The amount ofthe catalyst is generally from about 0.001 mol to about 0.02 mol, forexample from about 0.001 to about 0.01 mol, catalyst per mol of compoundof the formula II, depending on the reactivity of the compounds to bereacted, the catalyst and the reaction conditions chosen. In oneembodiment of the invention tetrakis(triphenylphosphine)palladium(0) orBDFP are employed as catalysts in the reaction of the compounds of theformula II with the compounds of the formula III.

Suzuki reactions and similar cross-coupling reactions are generallyperformed in the presence of a base. Examples of bases which can beemployed in the reaction of the compounds of the formula II with thecompounds of the formula III, are alkali metal carbonates like sodiumcarbonate, potassium carbonate or cesium carbonate, alkali metalphosphates like tripotassium phosphate, alkali metal hydroxides likesodium hydroxide or potassium hydroxide, alkali metal fluorides likepotassium fluoride or cesium fluoride, and suitable amines liketriethylamine, diisopropylethylamine or1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). In one embodiment of theinvention an alkali metal carbonate, for example sodium carbonate, isemployed as base in the reaction of the compounds of the formula II withthe compounds of the formula III.

Boronic acids and boronic acid esters of the formula III can be obtainedvia various procedures for the synthesis of such compounds described inthe literature, for example from organometallic compounds, such asorganolithium compounds or Grignard compounds which can in turn beobtained from the respective halides, i.e. compounds of the formulaG-E-A-halogen in which the groups A, E and G are defined as in thecompound of the formula I and in addition functional groups can bepresent in protected form or in the form of a precursor group, such asthe respective bromides and iodides, by reaction with borate esters,such as trimethyl borate or triisopropyl borate (cf. A. E. Smith et al.,Eur. J. Org. Chem. 2008, 1458-1463; W. Li et al., Org. Synth. 2009, 81,89-97; for example), or from the respective halides and diboronic acid(tetrahydroxydiboron) or diboronic acid esters such as the pinacol ester(bis(pinacolato)diboron,4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bi-1,3,2-dioxaborolane) in thepresence of a palladium catalyst (cf. T. Ishiyama et al., Tetrahedron2001, 57, 9813-9816; G. A. Molander et al., J. Am. Chem. Soc. 2010, 132,17701-17703, for example). In view of the wide synthetic utility ofboronic acids and boronic acid esters, a large number of compounds ofthe formula III and related boronic acids and boronic acid esters, whichcan be used to prepare the compounds of the formula I according to thepresent invention, are commercially available.

Compounds of the formula II in which the group X is chlorine, bromine oriodine, can be obtained according to standard procedures for aromaticchlorination, bromination and iodination, for example by means ofN-chlorosuccinimide (NCS), N-bromosuccinimide (NBS) andN-iodosuccinimide (NIS) (cf. S. M. Maddox et al., Org. Lett. 2015, 17,1042-1045; R. H. Mitchell et al., J. Org. Chem. 1979, 44, 4733-4735; K.Rajesh et al., J. Org. Chem. 2007, 72, 5867-5869; G. K. S. Prakash etal., J. Am. Chem. Soc. 2004, 126, 15770-15776, for example). Theseagents can also be used for the introduction of halogen substituents inother positions of the pyrido[3,4-b]indole ring system, such as inposition 6, depending on the substitution pattern in the respectivestarting compound and the reaction conditions. For example, suitablysubstituted compounds of the formula IV can be converted into compoundsof the formula IIa in which the group X^(a) is chlorine, bromine oriodine, by treatment with NCS, NBS or NIS, which together areabbreviated herein as NX^(a)S, for example in a solvent such as water inthe presence of an acid such as hydrochloric acid, sulfuric acid orphosphoric acid at temperatures from about 20° C. to about 100° C.

Similarly can compounds of the formula IVa, in which the group R⁵² ischlorine, bromine or iodine, be obtained by treatment of suitablysubstituted compounds of the formula V with NX^(a)S, for examplecompounds of the formula IVa in which R⁵² is chlorine by treatment withNCS in water and hydrochloric acid.

The groups R¹ to R⁶ and R¹⁰ in the compound of the formula IIa, IV, IVaand V are defined as in the compound of the formula I, and in additioncan functional groups be present in protected form or in the form of aprecursor group. Compounds of the formula IVa in which R^(5a) ischlorine can then be converted, for example by treatment with NBS orNIS, into compounds of the formula IIa in which R⁵ is chlorine and X^(a)is bromine or iodine, which can then be reacted with compounds of theformula III to give compounds of the formula I in which R⁵ is chlorine,for example.

Compounds of the formula II and related compounds useful for thepreparation of compounds of the formula II such as compounds of theformula IV and V can be prepared according to various processesdescribed in the literature, or analogously to processes described inthe literature, and many of them are commercially available, such as thecompounds harmane (1-methyl-9H-pyrido[3,4-b]indole), norharmane(9H-pyrido[3,4-b]indole), 6-chloro-9H-pyrido[3,4-b]indole,6-bromo-9H-pyrido[3,4-b]indole, 6-chloro-1-methyl-9H-pyrido[3,4-b]indoleor 6-bromo-1-methyl-9H-pyrido[3,4-b]indole, for example. Examples ofwell-known processes of which use can be made in the preparation ofcompounds of the formula II and related compounds, which start fromindole precursors which in turn are available via various processesdescribed in literature, are processes involving Bischler-Napieralskitype cyclizations or Pictet-Spengler type cyclizations and thecyclization of indole derivatives comprising two oxo-substituted groupsin positions 2 and 3 of the indole ring system.

From suitably substituted indole derivatives of the formula VI carryingan optionally substituted 2-acylamino-ethyl moiety in position 3 of theindole ring system, compounds of the formula VII can be obtained in aBischler-Napieralski type cyclization by treatment with phosphorusoxychloride (phosphoryl trichloride) or a mixture of phosphorusoxychloride and phosphorus pentoxide at elevated temperatures, such asat temperatures from about 60° C. to about 120° C., for example at about80° C., in an inert solvent such as a hydrocarbon like benzene or anitrile like acetonitrile or without a solvent. The compounds of theformula VII are then oxidized, or dehydrogenated, to compounds of theformula VIII, for example by treatment with nitrobenzene at elevatedtemperatures, such as at about reflux temperature, or by treatment withpotassium dichromate in a solvent such as water and acetic acid atelevated temperatures, such as at about reflux temperature of thesolvent.

From suitably substituted indole derivatives of the formula IX carryingan optionally substituted 2-amino-ethyl moiety in position 3 of theindole ring system, and aldehydes of the formula X compounds of theformula XI can be obtained in a Pictet-Spengler type cyclization, forexample under acidic conditions such as in water in the presence ofsulfuric acid at elevated temperatures, such as at about 65° C., or inan alcohol such as ethanol in the presence of hydrochloric acid atelevated temperatures, such as at about reflux temperature of thesolvent (cf. E. D. Cox et al., Chem. Rev. 1995, 95, 1797-1842, forexample). The compounds of the formula XI are then oxidized, ordehydrogenated, to compounds of the formula VIII, for example bytreatment with potassium dichromate in a solvent such as water andacetic acid at elevated temperatures, such as at about refluxtemperature of the solvent, or by treatment with palladium in a solventsuch as xylene at elevated temperatures, such as at about refluxtemperature of the solvent.

In another synthetic approach to compounds of the formula II and relatedcompounds suitably substituted indole derivatives of the formula XII,which can be obtained by acylating indole derivatives carrying anoptionally substituted 2-oxo-ethyl group in position 3 of the indolering system with an acylating agent in the presence of a catalyst suchas zinc chloride, are cyclized to compounds of the formula VIII bytreatment with a source of ammonia, such as an ammonium salt likeammonium acetate, in a solvent such as acetic acid at elevatedtemperatures, such as at about 60° C.

In a further synthetic approach aniline derivatives of the formula XIIIcarrying a 3-fluoro-pyridin-4-yl group in position 2, which can beobtained, for example, under the conditions of the Suzuki reaction oranother Suzuki-type reaction in the presence of transition metalcatalyst such as BDFP from the respective 2-bromo-aniline and a3-fluoro-pyridine carrying in position 4 a boronic acid group or acyclicor cyclic boronic acid ester group defined as the group of the formula(Y—O)₂—B— in the compounds of the formula II, are cyclized to compoundsof the formula VIII by treatment with a base, for example an alkalimetal compound such as an amide like lithium bis(trimethylsilyl)amide,in a solvent such as an ether like tetrahydrofuran or dioxane attemperatures of from about 20° C. to about 30° C., or with anothercyclization agent (cf. P. Rocca et al., Tetrahedron 1993, 49, 49-64; P.Rocca et al., Tetrahedron 1993, 49, 3325-3342).

The groups R³ to R⁶ and R¹³ in the compounds of the formulae VI, VII,VIII, IX, XI, XII and XIII are defined as in the compounds of theformula I, and in addition can functional groups be present in protectedform or in the form of a precursor group. The group R^(1a) in thecompounds of the formulae VI, VII, VIII, X, XI, XII and XIII is selectedfrom the series consisting of hydrogen and (C₁-C₄)-alkyl, in oneembodiment from the series consisting of hydrogen and (C₁-C₂)-alkyl, inanother embodiment from the series consisting of hydrogen and C₁-alkyl,and in another embodiment is hydrogen and in another embodiment is(C₁-C₄)-alkyl, for example C₁-alkyl. The group R^(2a) in the compoundsof the formulae VI, VII, VIII, IX, XI, XII and XIII is selected from theseries consisting of hydrogen, (C₁-C₄)-alkyl and (C₁-C₄)-alkyl-O—C(O)—,in one embodiment from the series consisting of hydrogen and(C₁-C₄)-alkyl, in another embodiment from the series consisting ofhydrogen and (C₁-C₂)-alkyl, in another embodiment from the seriesconsisting of hydrogen and C₁-alkyl, and in another embodiment ishydrogen and in another embodiment is (C₁-C₄)-alkyl, for exampleC₁-alkyl. The group Z in the compounds of the formulae VI, VII, VIII,IX, XI, XII and XIII is selected from the series consisting of hydrogen,chlorine, bromine, iodine, hydroxy and (C₁-C₄)-alkyl-O—, in oneembodiment from the series consisting of hydrogen, chlorine, bromine andiodine, in another embodiment from the series consisting of hydrogen,bromine and iodine, in another embodiment from the series consisting ofchlorine, bromine and iodine, in another embodiment from the seriesconsisting of bromine and iodine, in another embodiment from the seriesconsisting of hydroxy and (C₁-C₄)-alkyl-O—, in another embodiment it ishydrogen, and in another embodiment it is bromine. Compounds of theformula VIII in which Z is chlorine, bromine or iodine, are compounds ofthe formulae II and IIa which can be used in the reaction with compoundsof the formula III to give compounds of the formula I. Compounds of theformula VIII in which Z is hydrogen, can be converted into compounds ofthe formulae II and IIa, which can be used in the reaction withcompounds of the formula III to give compounds of the formula I, byhalogenation as outlined above. Compounds of the formula VIII in which Zis (C₁-C₄)-alkyl-O—, can be converted into compounds of the formula VIIIin which Z is hydroxy under standard condition for the cleavage of alkylethers, for example by treatment with boron tribromide. Compounds of theformula VIII in which Z is hydroxy can be converted under standardconditions into compounds of the formula II in which the group X is asulfonyloxy group, for example a trifluoromethanesulfonyloxy group whichcan be introduced by treatment of the compound of the formula VIII withtrifluoromethanesulfonic acid anhydride, and the obtained compound ofthe formula II be used in the reaction with compounds of the formula IIIto give compounds of the formula I.

As mentioned above, the group R¹⁰ in the compounds of the formulae II,IIa, IV, IVa, V, VI, VII, VIII, IX, XI, XII and XIII is defined as inthe compounds of the formula I, and in addition can functional groups bepresent in protected form or in the form of a precursor group, and canthus be hydrogen, or be different from hydrogen and be an optionallysubstituted (C₁-C₆)-alkyl group, (C₂-C₆)-alkenyl group, (C₂-C₆)-alkynylgroup and optionally substituted (C₃-C₇)-cycloalkyl group. Groups R¹⁰which are different from hydrogen, can be present in the startingcompound for the synthesis of a compound of the formula I or introducedat any stage in course of the synthesis, for example in a compound ofthe formula II, IIa, IV, IVa, V or VIII, as well as in a final compoundof the formula I according to the invention, by reaction of therespective compound in which R¹⁰ is hydrogen with an electrophiliccompound of the formula XIV, for example an alkylating agent if anoptionally substituted alkyl group representing R¹⁰ is to be introduced,as illustrated by the example of a compound of the formula IIb, which isa compound of the formula IIa in which R¹⁰ is hydrogen and can beconverted by reaction with a compound of the formula XIV into a compoundof the formula IIc.

The groups R¹ to R⁶ and X in the compounds of the formulae IIb and IIcare defined as in the compounds of the formula IIa. The group R^(10a) inthe compounds of the formulae IIc and XIV is selected from the seriesconsisting of (C₁-C₆)-alkyl, (C₂-C₆)-alkenyl, (C₂-C₆)-alkynyl and(C₃-C₇)-cycloalkyl, wherein alkyl is unsubstituted or substituted by 1or 2 identical or different substituents selected from the seriesconsisting of (C₃-C₇)-cycloalkyl, Het, cyano and (C₁-C₄)-alkyl-O—,wherein all cycloalkyl groups are unsubstituted or substituted by one ormore identical or different substituents selected from the seriesconsisting of fluorine and (C₁-C₄)-alkyl. The group L in the compoundsof the formula XIV is a nucleophilically substitutable leaving group,such as halogen selected from the series consisting of chlorine, bromineand iodine, or a sulfonyloxy group like methanesulfonyloxy,trifluoromethanesulfonyloxy or 4-toluenesulfonyloxy, for example. Thereaction of compounds of the formula IIb and compounds of the formulaeI, II, IV, IVa, V or VIII in which R¹⁰ is hydrogen, with compounds ofthe formula XIV can be performed under standard conditions for thereaction of electrophilic compounds such as alkylating agents, forexample, with nitrogen heterocycles and other nitrogen compounds inwhich a hydrogen atom on the nitrogen atom can be replaced by a groupsuch as an alkyl group, for example. In a favorable manner suchreactions are performed in the presence of a base, such an alkali metalhydride like sodium hydride or an alkali metal alkoxide like sodiumethoxide or sodium tert-butoxide or an alkali metal carbonate likepotassium carbonate or cesium carbonate, in an inert solvent, such as anamide like dimethylformamide or N-methyl-2-pyrrolidone or a ketone likeacetone or butan-2-one or an ether like tetrahydrofuran or dioxane, attemperatures of from about 20° C. to about 100° C., for exampletemperatures of from about 20° C. to about 60° C. In one embodiment, thereaction of a compound of the formula IIb or a compound of the formulaeI, II, IV, IVa, V or VIII in which R¹⁰ is hydrogen, with a compound ofthe formula XIV is performed in the presence of an alkali metalcarbonate like potassium carbonate or cesium carbonate in a solvent likedimethylformamide at temperatures of from about 20° C. to about 30° C.

In another process a compound of the formula I is prepared by chemicalmodification, or introduction or transformation of functional groups, ofa compound which has been prepared from a compound of the formula II anda compound of the formula III as described above. The compound that ismodified chemically can be a compound of the formula I according to thepresent invention, as well as a compound which is not covered by thedefinition of the compounds of the formula I according to the presentinvention. Such chemical modifications can be performed in the moietyG-E-A- or in the groups R¹ to R⁶ and R¹⁰, for example. Such chemicalmodifications can also be performed in another stage of the synthesis ofthe compounds of the formula I, for example in compounds of the formulaII.

For example, a hydroxy group can be reacted with a carboxylic acid inthe presence of an activating agent, such as carbodiimide or anN,N′-carbonyldiazole or another customary coupling reagent, or with areactive carboxylic acid derivative such as a carboxylic acid chlorideto give an acyloxy group, i.e. a carboxylic acid ester group. A hydroxygroup can be etherified by alkylation with a halogen compound, forexample a bromide or iodide, in the presence of a base such an alkalimetal hydride like sodium hydride or an alkali metal carbonate likepotassium carbonate or cesium carbonate in an inert solvent such as anamide like dimethylformamide or N-methyl-2-pyrrolidone or a ketone likeacetone or butan-2-one at temperatures of from about 20° C. to about120° C., or with the respective alcohol under the conditions of theMitsunobu reaction in the presence of a phosphine liketriphenylphosphine or tributylphosphine and an azodicarboxylic acidderivative like diethyl azodicarboxylate or diisopropyl azodicarboxylatein an inert solvent such as an ether like tetrahydrofuran. An ethergroup initially present can be cleaved, for example by means of borontribromide or an acid, and the resulting hydroxy group then convertedinto various other groups. By reaction with an isocyanate, a hydroxygroup can be converted into an N-substituted carbamic acid ester. Bytreatment with a halogenating agent such as thionyl chloride or aphosphorus halide a hydroxy group can be replaced by a halogen atom.

Halogen atoms can also be introduced according to various otherprocedures described in the literature. Fluorine atoms can be introducedby means of reagents such as diethylaminosulfur trifluoride orN-fluoro-2,4,6-trimethylpyridinium triflate, for example, and similarreagents. A halogen atom, as well as a hydroxy group after activation byconversion into a reactive leaving group such as a methanesulfonyloxygroup, trifluoromethanesulfonyloxy group or 4-toluenesulfonyloxy group,can be replaced with a variety of groups, including groups such ascyano, trifluoromethyl, pentafluoroethyl, carboxylic acid, carboxamide,amino, alkyl, aryl or heterocyclic groups, in a substitution reaction,which may also be catalyzed by transition metals such as by a palladiumcatalyst, a nickel catalyst or a copper catalyst. By halogen/metalexchange, as well as by hydrogen/metal exchange, for example bytreatment within organolithium compound, and subsequent reaction with awide range of electrophiles various substituents can be introduced.

A carboxylic acid ester group or a cyano group can be hydrolyzed underacidic or basic conditions to give a carboxylic acid. A cyano group canbe hydrolyzed partially to give a primary amide. A carboxylic acid groupcan be activated or converted into a reactive derivative as indicatedabove, and reacted with an alcohol or an amine or ammonia to give anester or amide. A carboxylic acid group, which may have been obtained bysaponification of an ester group, can be converted into a hydrogen atomby decarboxylation, for example by heating a metal salt of thecarboxylic acid. A primary amide can be dehydrated to give a nitrile. Acarboxylic acid group, carboxylic acid ester group, aldehyde group orketone group can be reduced to an alcohol, for example with a complexhydride such as lithium aluminium hydride, lithium borohydride or sodiumborohydride, or reacted with an organometal compound such as a Grignardcompound, for example, to give an alcohol. A hydroxy group can beoxidized to an oxo group, for example by means of pyridiniumchlorochromate or the Dess-Martin periodinane reagent.

An amino group and a suitable ring nitrogen atom in a heterocycle can bemodified under standard conditions for acylation or sulfonylation, forexample by reaction with an activated carboxylic acid or a reactivecarboxylic acid derivative like a carboxylic acid chloride or anhydride,or a sulfonyl chloride. An amino group and a suitable ring nitrogen atomin a heterocycle can be alkylated by reaction with optionallysubstituted alkyl halogenides like chlorides, bromides or iodides orsulfonyloxy compounds like toluenesulfonyloxy, methanesulfonyloxy ortrifluoromethanesulfonyloxy compounds, generally in the presence of abase such as potassium carbonate, cesium carbonate, sodium hydride orpotassium tert-butoxide, for example, or by reductive amination ofcarbonyl compounds in the presence of a complex hydride reducing agent.A nitro group can be reduced to an amino group with various reducingagents, such as sulfides, dithionites, iron, complex hydrides or bycatalytic hydrogenation. A cyano group and a carboxamide group can bereduced to an amino-substituted methyl group. A sulfur atom in analkyl-S— group or in a heterocyclic ring can be oxidized with a peroxidelike hydrogen peroxide or a peracid to give a sulfoxide moiety (S(O)) ora sulfone moiety (S(O)₂).

All such reactions useful for the preparation of compounds of theformula I are known per se and can be carried out in a manner familiarto a person skilled in the art according to, or analogously, toprocedures which are described in the standard literature, for examplein Houben-Weyl, Methods of Organic Chemistry, Thieme; or OrganicReactions, John Wiley & Sons; or R. C. Larock, Comprehensive OrganicTransformations: A Guide to Functional Group Preparations, 2. ed.(1999), John Wiley & Sons, and the references quoted therein. As appliesin general and is known to the person skilled in the art, it may incertain cases become necessary to specifically adapt reaction conditionsor choose specific reagents from a variety of reagents that can inprinciple be employed in a reaction, or otherwise take specific measuresfor achieving a desired conversion, for example to use protection grouptechniques.

In the course of the preparation of the compounds of the formula I itcan generally be advantageous or necessary in order to reduce or preventundesired reactions or side reactions in a synthesis step, to blockfunctional groups temporarily by protecting groups suited to thespecific synthesis problem, or to have them present, or introduce them,in the form of precursor groups, and later convert them into the desiredfunctional groups. This applies to all reactions in the course of thesynthesis of the compounds of the formula I including the synthesis ofintermediates and the synthesis of starting compounds and buildingblocks. Such strategies are well known to a person skilled in the artand are described, for example, in P. G. M. Wuts and T. W. Greene,Greene's Protective Groups in Organic Synthesis, 4. ed. (2007), JohnWiley & Sons. Examples of precursor groups are cyano groups and nitrogroups. As already mentioned, a cyano group can in a later step betransformed by hydrolysis into a carboxylic acid derivative or byreduction into a aminomethyl group, and a nitro group can be transformedby reduction like catalytic hydrogenation into an amino group. Examplesof protective groups which may be mentioned, are benzyl protectivegroups, for example benzyl ethers of hydroxy compounds and benzyl estersof carboxylic acids, from which the benzyl group can be removed bycatalytic hydrogenation in the presence of a palladium catalyst,tert-butyl protective groups, for example tert-butyl esters ofcarboxylic acids or tert-butyl ethers of hydroxy groups, from which thetert-butyl group can be removed by treatment with trifluoroacetic acid,acyl protective groups, for example ester and amides of hydroxycompounds and amino compounds, which can be cleaved again by acidic orbasic hydrolysis, or alkoxycarbonyl protective groups, for exampletert-butoxycarbonyl derivatives of amino compounds, which can be cleavedagain by treatment with trifluoroacetic acid.

In all processes for the preparation of the compounds of the formula I,workup of the reaction mixture and the purification of the product isperformed according to customary methods known to the skilled personwhich include, for example, quenching of a reaction mixture with water,adjustment of a certain pH, precipitation, extraction, drying,concentration, crystallization, distillation and chromatography. Asfurther examples of methods applicable in the synthesis of the compoundsof the formula I, microwave assistance for speeding-up, facilitating orenabling reactions may be mentioned, and separation techniques likepreparative high pressure liquid chromatography (HPLC), which can beused for separating mixtures of isomers which may occur in a reaction.Also for the characterization of the products, customary methods areused, such as NMR, UV, IR and mass spectroscopy.

Another subject of the present invention are the novel startingcompounds and intermediates occurring in the synthesis of the compoundsof the formula I, including the compounds of the formulae II, IIa, IIb,IIc, III, IV, IVa, V, VI, VII, VIII, IX, XI, XII, XIII and XIV, whereinthe groups R¹ to R⁶, R^(1a), R^(2a), R^(5a), R^(10a), L, X, X^(a), Y andZ are defined as above, in any of their stereoisomeric forms or amixture of stereoisomeric forms in any ratio, and their salts, and theiruse as synthetic intermediates or starting compounds. All generalexplanations, specifications of embodiments and definitions of numbersand groups given above with respect to the compounds of the formula Iapply correspondingly to the said intermediates and starting compounds.A subject of the invention are in particular the novel specific startingcompounds and intermediates described herein. Independently thereofwhether they are described as a free compound and/or as a specific salt,they are a subject of the invention both in the form of the freecompounds and in the form of their salts, and if a specific salt isdescribed, additionally in the form of this specific salt.

The compounds of the formula I and their pharmaceutically acceptablesalts according to the present invention stimulate chondrogenesis andcartilage formation and induce the formation of articular cartilagematrix components and of SOX transcription factors, in particular SOX-5,SOX-6 and SOX-9, and are useful as active drug substances inpathological conditions in which chondrogenesis or cartilage formationis decreased or inappropriate or a stimulation of chondrogenesis orcartilage formation or induction of the formation of articular cartilagematrix components or SOX transcription factors is desired, such as inthe therapy or prophylaxis of osteoarthritis and other diseasesmentioned above or below. The activity of the compounds of the formula Ican be determined in the assays described below or in other in vitro, exvivo or in vivo assays and models known to the person skilled in theart. To allow the comparison of compound activities determined indifferent experiments, given the natural biological variation of thechondrogenic response between different experiments, in thedetermination of the activity of the compounds in assays such as thosedescribed below an internal reference compound at a constantconcentration is included in all experiments, and the activity of thecompounds, such as collagen type II induction or proteoglycan induction,is calculated in percent in relation to the internal reference compoundat its concentration. As internal reference compound any active compoundcan be used, for example the compound1-methyl-8-[4-(quinolin-2-ylmethoxy)phenoxy]-4,5-dihydro-1H-thieno[3,4-g]indazole-6-carboxamideknown as TD-198946 (F. Yano et al., Ann. Rheum. Dis. 2013, 72, 748-753),or a compound of the present invention such as the compound of example28, for example.

Because of their pharmacological properties, the compounds of thepresent invention are suitable for the treatment of all disorders in theprogression of which a reduced or insufficient chondrogenesis orcartilage formation or level of SOX transcription factors is involvedincluding, for example, the indications described in the introduction ofthe present application. The invention relates in particular to the useof a compound of the formula I or a pharmaceutically acceptable saltthereof for the treatment of degenerative joint disorders anddegenerative cartilage changes including osteoarthritis, primaryosteoarthritis, secondary osteoarthritis, age-related erosive handosteoarthritis, osteoarthrosis, rheumatoid arthritis, misalignmentsyndromes of joints, spondylosis, chondrolysis following joint trauma orprolonged joint immobilization after meniscus or patella injuries orligament tears and degenerative disk diseases; any type of fibrosis andinflammatory processes; pain including acute pain like pain followinginjuries and post-operative pain and chronic pain like pain associatedwith chronic musculoskeletal diseases, back pain, pain associated withosteoarthritis or rheumatoid arthritis and pain associated withinflammation; chronic disorders of the locomotor system such asinflammatory, immunologically or metabolically related acute and chronicarthritides, arthropathies, myalgias and disturbances of bonemetabolism; connective tissue disorders such as collagenoses, andwound-healing disturbances; for example. The treatment of diseases suchas degenerative joint disorders, degenerative cartilage changes,osteoarthritis, misalignment syndromes of joints or degenerative diskdiseases, for example, can be carried out in various joints includingknee, hip, shoulder, elbow and hand joints and intervertebral joints,and includes also the aspect of regeneration of the cartilage or of ameniscus in a joint and intervertebral disc regeneration, respectively.

The treatment of diseases is to be understood herein as generallymeaning both the therapy of existing pathological changes ormalfunctions of the organism or of existing symptoms with the aim ofrelief, alleviation or cure in a subject in need thereof, and theprophylaxis or prevention of pathological changes or malfunctions of theorganism or of symptoms in a subject susceptible thereto and in need ofsuch a prophylaxis or prevention, with the aim of a prevention orsuppression of their occurrence or of an attenuation in the case oftheir occurrence. In one embodiment of the invention the treatment ofdiseases is the therapy of existing pathological changes ormalfunctions, in another embodiment it is the prophylaxis or preventionof pathological changes or malfunctions. The treatment of diseases canoccur both in acute cases and in chronic cases.

The compounds of the formula I and their pharmaceutically acceptablesalts can therefore be used in animals, in particular in mammals andspecifically in humans, as a pharmaceutical or medicament on their own,in mixtures with one another, or in the form of pharmaceuticalcompositions. A subject of the present invention also are the compoundsof the formula I and their pharmaceutically acceptable salts for use asa pharmaceutical. A subject of the present invention further arepharmaceutical compositions and medicaments which comprise at least onecompound of the formula I and/or a pharmaceutically acceptable saltthereof as an active ingredient, in an effective dose for the desireduse, and a pharmaceutically acceptable carrier, i.e. one or morepharmaceutically innocuous, or nonhazardous, vehicles and/or excipients,and optionally one or more other pharmaceutically active compounds.

A subject of the present invention are also the compounds of the formulaI and their pharmaceutically acceptable salts for use in the treatmentof the diseases mentioned above or below, including the treatment of anyone of the mentioned diseases, for example the treatment of degenerativejoint disorders, degenerative cartilage changes, fibrosis, inflammatoryprocesses or pain, wherein treatment of diseases comprises their therapyand prophylaxis as mentioned above, or for use as a stimulator ofchondrogenesis or cartilage formation or as an inducer of SOXtranscription factors. A subject of the present invention also are theuse of the compounds of the formula I and their pharmaceuticallyacceptable salts for the manufacture of a medicament for the treatmentof the diseases mentioned above or below, including the treatment of anyone of the mentioned diseases, for example the treatment of degenerativejoint disorders, degenerative cartilage changes, fibrosis, inflammatoryprocesses or pain, wherein treatment of diseases comprises their therapyand prophylaxis as mentioned above, or a medicament for stimulatingchondrogenesis or cartilage formation or inducing SOX transcriptionfactors. A subject of the present invention are also methods for thetreatment of the diseases mentioned above or below, including thetreatment of any one of the mentioned diseases, for example thetreatment of degenerative joint disorders, degenerative cartilagechanges, fibrosis, inflammatory processes or pain, wherein treatment ofdiseases comprises their therapy and prophylaxis as mentioned above, andmethods for stimulating chondrogenesis or cartilage formation orinducing SOX transcription factors, which comprise administering anefficacious amount of at least one compound of the formula I and/or apharmaceutically acceptable salt thereof to a subject in need thereof. Asubject of the present invention further are the compound8-phenyl-9H-pyrido[3,4-b]indole and its pharmaceutically acceptablesalts for use as a pharmaceutical, pharmaceutical compositions andmedicaments which comprise the compound 8-phenyl-9H-pyrido[3,4-b]indoleand/or a pharmaceutically acceptable salt thereof and a pharmaceuticallyacceptable carrier, and the compound 8-phenyl-9H-pyrido[3,4-b]indole andits pharmaceutically acceptable salts for use in the treatment of thediseases mentioned above or below, including the treatment of any one ofthe mentioned diseases, for example the treatment of degenerative jointdisorders, degenerative cartilage changes, fibrosis, inflammatoryprocesses or pain, wherein treatment of diseases comprises their therapyand prophylaxis as mentioned above, or for use as a stimulator ofchondrogenesis or cartilage formation or as an inducer of SOXtranscription factors.

The compounds of the formula I and their pharmaceutically acceptablesalts, and pharmaceutical compositions and medicaments comprising them,can be administered enterally, for example by oral or rectaladministration in the form of pills, tablets, lacquered tablets, coatedtablets, granules, hard and soft gelatin capsules, solutions, syrups,emulsions, suspensions, aerosol mixtures or suppositories, orparenterally. Parenteral administration can be carried out, for example,intravenously, intra-articularly, intraperitoneally, intramuscularly orsubcutaneously, for example by injection or infusion, in the formsolutions, suspensions, microcapsules, implants or rods or othersuitable galenical forms. Administration can also be carried outtopically, percutaneously or transdermally, for example, and in otherways, the preferred form of administration being depending on theparticulars of the specific case. For topical administration to externaltissue, such as to the skin or in the mouth, formulations such asointments, creams, lotions, tinctures, powders, solutions, suspensions,pastes, gels, sprays, aerosols or oils can be used. Pharmaceuticalformulations adapted for transdermal administration can be administeredas plasters for extended, close contact with the epidermis of therecipient. In the case of ointments, the active ingredient can beemployed either with a paraffinic or a water-miscible cream base, andthe active ingredient can be formulated to give a cream with anoil-in-water cream base or a water-in-oil cream base.

The pharmaceutical compositions according to the invention are preparedin a manner known per se and familiar to the person skilled in the artby admixing one or more pharmaceutically acceptable inert inorganicand/or organic vehicles and excipients with one or more compounds of theformula I and/or pharmaceutically acceptable salts thereof, and bringingthem into a suitable form for dosage and administration, which can thenbe used in human medicine or veterinary medicine. For the production ofpills, tablets, coated tablets and hard gelatin capsules it is possibleto use, for example, lactose, cornstarch or derivatives thereof, talc,stearic acid or its salts. For the production of gelatin capsules andsuppositories fats, waxes, semisolid and liquid polyols, natural orhardened oils, for example, can be used. For the production ofsolutions, for example injection solutions, or of emulsions or syrupswater, saline, alcohols, glycerol, polyols, sucrose, invert sugar,glucose, vegetable oils, for example, can be used, and for theproduction of microcapsules, implants or rods copolymers of glycolicacid and lactic acid, for example, can be used. The pharmaceuticalcompositions normally contain from about 0.5% to about 90% by weight ofthe compounds of the formula I and/or their pharmaceutically acceptablesalts. The amount of the active ingredient of the formula I and/or itspharmaceutically acceptable salts in the pharmaceutical compositionsnormally is from about 0.1 mg to about 1000 mg, for example from about 1mg to about 500 mg, per unit dose. Depending on the kind of thepharmaceutical composition and other particulars of the specific case,the amount may deviate from the indicated ones.

In addition to the active ingredients of the formula I and/or theirpharmaceutically acceptable salts and to vehicles, or carriersubstances, the pharmaceutical compositions can contain excipients, orauxiliaries or additives, such as, for example, fillers, disintegrants,binders, lubricants, wetting agents, stabilizers, emulsifiers,preservatives, sweeteners, colorants, flavorings, aromatizers,thickeners, diluents, buffer substances, solvents, solubilizers, agentsfor achieving a depot effect, salts for altering the osmotic pressure,coating agents or antioxidants. They can also contain two or morecompounds of the formula I, and/or their pharmaceutically acceptablesalts. In case a pharmaceutical composition contains two or morecompounds of the formula I, the selection of the individual compoundscan aim at a specific overall pharmacological profile of thepharmaceutical composition. For example, a highly potent compound with ashorter duration of action may be combined with a long-acting compoundof lower potency. The flexibility permitted with respect to the choiceof substituents in the compounds of the formula I allows a great deal ofcontrol over the biological and physico-chemical properties of thecompounds and thus allows the selection of such desired compounds.

When using the compounds of the formula I in the treatment of diseases,the dose can vary within wide limits and, as is customary and is knownto the physician, is to be suited to the individual conditions in eachindividual case. It depends, for example, on the specific compoundemployed, on the nature and severity of the disease to be treated, onthe mode and the schedule of administration, or on whether an acute orchronic condition is treated or whether prophylaxis is carried out. Anappropriate dosage can be established using clinical approaches known tothe person skilled in the art. In general, in the case of a dailyadministration the daily dose for achieving the desired results in anadult weighing about 75 kg is from about 0.01 mg/kg to about 100 mg/kg,for example from about 0.1 mg/kg to about 50 mg/kg, such as from about0.1 mg/kg to about 10 mg/kg, in each case in mg per kg of body weight.The daily dose can be divided, in particular in the case of theadministration of relatively large amounts, into several, for example 2,3 or 4, part administrations. In the case of intra-articularadministration, which usually is carried at longer time intervals, suchas weekly or bi-weekly or monthly, for example, the dose peradministration in general is from about 0.1 mg per joint to about 100 mgper joint, for example from about 0.5 mg per joint to about 50 mg perjoint, such as from about 1 mg per joint to about 75 mg per joint. Asusual, depending on individual behavior it may be necessary to deviateupwards or downwards from the doses indicated.

The compounds of the present invention are also useful as standard orreference compounds in tests or assays involving chondrogenesis orinduction of SOX transcription factors. For such use, for example inpharmaceutical research, the compounds may be provided in a commercialkit. For example, a compound of the present invention can be used as areference in an assay to compare its known activity to a compound withan unknown activity. Furthermore, the compounds of the formula I can beused as synthesis intermediates for the preparation of other compounds,in particular of other pharmaceutically active compounds, which may beobtained from the compounds of the formula I by introduction ofsubstituents or modification of functional groups, for example.

The following examples illustrate the present invention.

EXAMPLES

Abbreviations used are explained below or correspond to the usualconventions.

-   ACN acetonitrile-   BDFP 1,1′-bis(diphenylphosphino)ferrocene-palladium(II) dichloride    dichloromethane complex-   DCM dichloromethane-   DMF N,N-dimethylformamide-   DMSO dimethyl sulfoxide-   EA ethyl acetate-   FA formic acid-   HEP n-heptane-   MeOH methanol-   RT retention time-   TFA trifluoroacetic acid-   THF tetrahydrofuran

When example compounds containing a basic group were purified bypreparative high pressure liquid chromatography (HPLC) on reversed phase(RP) column material and, as customary, the eluent was a gradientmixture of water and acetonitrile containing an acid such astrifluoroacetic acid, they were usually obtained in part or completelyin the form of their acid addition salts such as the salt withtrifluoroacetic acid, depending on the details of the workup such asevaporation or lyophilization conditions. In the names in the heading ofthe examples and the structural formulae such a trifluoroacetic acidcomponent of an example compound, as well as the acid component of otheracid addition salts such as hydrochlorides, for example, in the form ofwhich part of the example compounds have been isolated, is generally notspecified.

Reactions were generally performed under argon as protective gas.Solvents such as dichloromethane, ethanol, dimethylformamide, methanol,tetrahydrofuran and the like were generally employed as commerciallyavailable dry solvents. “Room temperature” means a temperature of 20° C.to 25° C. Reactions under microwave irradiation were carried out in aPersonal Chemistry Emrys Optimizer microwave synthesizer in vessels ofcapacities from 0.5 ml to 20 ml. Solvents were generally evaporatedunder reduced pressure at temperatures ranging from 35° C. to 45° C. ona rotary evaporator. Chromatography over silica gel was carried outmanually (flash chromatography) or supported by semiautomatic cartridgesystems such as Companion (CombiFlash) or Flashmaster II (JonesChromatography). Purifications by preparative RP HPLC were generallyperformed with columns of a diameter of 25 mm or 30 mm and a length of250 mm filled with RP18 silica gel of 10 μm particle size, eluting witha gradient of water and acetonitrile containing trifluoroacetic acid orhydrochloric acid.

The example compounds were generally characterized by analytical HPLCwith ultraviolet detection at 220 nm and 254 nm and mass spectrometry(MS) detection with electrospray ionization (ESI) (LCUV/ESI-MS coupling;LC/MS), and by ¹H nuclear magnetic resonance spectroscopy (¹H NMR). TheLC/MS analyses were based on the UV chromatograms at 220 nm and 254 nmand the ion current from the mass spectrometer at different ionisationmodes (e.g. ESI+, ESI−) with the help of ion extracts of the expectedion masses. ¹H NMR spectra were recorded at 400 MHz or 500 MHz or 600MHz in DMSO-d₆ as solvent at 298 K, unless specified otherwise. In theNMR characterization, the chemical shift 6 (in ppm) and themultiplicities (s=singlet, d=doublet, t=triplet, q=quartet, dd=doubletof doublets, br=broad) and the number of hydrogen atoms (H) of the peaksare given. In the LC/MS characterization, the HPLC method specifiedbelow, the retention time (RT) in minutes, and generally themass-to-charge-ratio m/z of the peak of the molecular ion representingthe monoisotopic mass, or of a related ion which was formed depending onthe ionization mode, is given. In most cases, the ionization mode waspositive electrospray ionization (ESI+), and the mass-to-charge-ratio ofthe ion [M+H]⁺ is given. When no significant [M+H]⁺ peak was obtained,the mass-to-charge-ratio of another characteristic mass signal such as[M+2H]⁺⁺ or an ion of an addition compound with a solvent molecule or[M−H]⁻, which was formed depending on the ionization mode, such asnegative electrospray ionization (ESI−) in the case of the latter ion,is given.

The particulars of the HPLC methods in the LC/MS characterization wereas follows.

Method LC1

Column: Merck Chromolith FastGrad RP-18e, 2×50 mm, monolithic; flow: 2.0ml/min; eluent A: water+0.05% TFA, eluent B: ACN+0.05% TFA; gradient:98% A: 2% B (0.0 min) to 98% A: 2% B (0.2 min) to 2% A: 98% B (2.4 min)to 2% A: 98% B (3.2 min) to 98% A: 2% B (3.3 min) to 98% A: 2% B (4.0min)

Method LC2

Column: Merck Chromolith FastGrad RP-18e, 2×50 mm, monolithic; flow: 2.4ml/min; eluent A: water+0.05% TFA, eluent B: ACN+0.05% TFA; gradient:98% A: 2% B (0.0 min) to 98% A: 2% B (0.2 min) to 2% A: 98% B (2.4 min)to 2% A: 98% B (3.2 min) to 98% A: 2% B (3.3 min) to 98% A: 2% B (4.0min)

Method LC3

Column: Waters UPLC BEH C18, 2.1×50 mm, 1.7 μm; flow: 0.9 ml/min;temperature 55° C.; eluent A: water+0.05% FA, eluent B: ACN+0.035% FA;gradient: 95% A: 5% B (0.0 min) to 5% A: 95% B (1.1 min) to 5% A: 95% B(1.7 min) to 95% A: 5% B (1.8 min) to 95% A: 5% B (2.0 min)

Method LC4

Column: Waters UPLC BEH C18, 2.1×50 mm, 1.7 μm; flow: 0.9 ml/min;temperature 55° C.; eluent A: water+0.05% FA, eluent B: ACN+0.035% FA;gradient: 95% A: 5% B (0.0 min) to 5% A: 95% B (2.0 min) to 5% A: 95% B(2.6 min) to 95% A: 5% B (2.7 min) to 95% A: 5% B (3.0 min)

Method LC5

Column: Waters UPLC BEH C18, 2.1×50 mm, 1.7 μm; flow: 0.9 ml/min;temperature 55° C.; eluent A: water+0.05% FA, eluent B: ACN+0.035% FA;gradient: 98% A: 2% B (0.0 min) to 5% A: 95% B (2.0 min) to 5% A: 95% B(2.6 min) to 98% A: 2% B (2.7 min) to 98% A: 2% B (3.0 min)

Method LC6

Column: Waters UPLC BEH C18, 2.1×50 mm, 1.7 μm; flow: 0.9 ml/min;temperature 55° C.; eluent A: water+0.1% FA, eluent B: ACN+0.08% FA;gradient: 95% A: 5% B (0.0 min) to 5% A: 95% B (1.1 min) to 5% A: 95% B(1.7 min) to 95% A: 5% B (1.8 min) to 95% A: 5% B (2.0 min)

Method LC7

Column: Waters XBridge C18, 4.6×50 mm, 2.5 μm; flow: 1.6 ml/min;temperature 30° C.; eluent A: water+0.1% FA, eluent B: ACN+0.08% FA;gradient: 97% A: 3% B (0.0 min) to 2% A: 98% B (18.0 min) to 2% A: 98% B(19.0 min) to 97% A: 3% B (19.5 min) to 97% A: 3% B (20.0 min)

Method LC8

Column: Waters XBridge C18, 4.6×50 mm, 2.5 μm; flow: 1.3 ml/min;temperature 30° C.; eluent A: water+0.1% FA, eluent B: ACN+0.1% FA;gradient: 97% A: 3% B (0.0 min) to 40% A: 60% B (3.5 min) to 2% A: 98% B(4.0 min) to 2% A: 98% B (5.0 min) to 97% A: 3% B (5.2 min) to 97% A: 3%B (6.5 min)

Method LC9

Column: Waters XBridge C18, 4.6×50 mm, 2.5 μm; flow: 1.7 ml/min;temperature 50° C.; eluent A: water+0.05% TFA, eluent B: ACN+0.05% TFA;gradient: 95% A: 5% B (0.0 min) to 95% A: 5% B (0.2 min) to 5% A: 95% B(2.4 min) to 5% A: 95% B (3.5 min) to 95% A: 5% B (3.6 min) to 95% A: 5%B (4.5 min)

Method LC10

Column: Waters XBridge C18, 4.6×50 mm, 2.5 μm; flow: 1.3 ml/min; eluentA: water+0.05% TFA, eluent B: ACN+0.05% TFA; gradient: 95% A: 5% B (0.0min) to 95% A: 5% B (0.3 min) to 5% A: 95% B (3.5 min) to 5% A: 95% B(4.0 min) to 95% A: 5% B (4.5 min)

Method LC11

Column: YMC-Pack Jsphere H80, 2.1×33 mm, 4.0 μm; flow: 1.0 ml/min;eluent A: water+0.05% TFA, eluent B: ACN+0.05% TFA; gradient: 98% A: 2%B (0.0 min) to 98% A: 2% B (1.0 min) to 5% A: 95% B (5.0 min) to 5% A:95% B (6.25 min)

Method LC12

Column: YMC-Pack Jsphere H80, 2.1×33 mm, 4.0 μm; flow: 0.9 ml/min;eluent A: water+0.05% TFA, eluent B: MeOH+0.05% TFA; gradient: 98% A: 2%B (0.0 min) to 98% A: 2% B (1.0 min) to 5% A: 95% B (5.0 min) to 5% A:95% B (6.25 min)

Method LC13

Column: Phenomenex Luna C18, 2.0×10 mm, 3.0 μm; flow: 1.1 ml/min; roomtemperature; eluent A: water+0.05% TFA, eluent B: ACN; gradient: 93% A:7% B (0.0 min) to 5% A: 95% B (1.2 min) to 5% A: 95% B (1.4 min) to 93%A: 7% B (1.45 min)

Method LC14

Column: Phenomenex Luna C18, 2.0×10 mm, 3.0 μm; flow: 1.1 ml/min; roomtemperature; eluent A: water+0.05% TFA, eluent B: ACN; gradient: 93% A:7% B (0.0 min) to 5% A: 95% B (1.0 min) to 5% A: 95% B (1.45 min) to 93%A: 7% B (1.5 min)

Exemplary Procedures for the Synthesis of Intermediates Intermediate 1.8-Bromo-6-chloro-9H-pyrido[3,4-b]indole

a) 6-Chloro-9H-pyrido[3,4-b]indole

N-Chlorosuccinimide (9.78 g, 73.29 mmol) was added in portions withexclusion of light to a solution of norharmane hydrochloride (10.0 g,48.86 mmol) in water (100 ml) and 1 M hydrochloric acid (100 ml). Themixture was stirred at room temperature overnight and subsequently for 2h with cooling in ice (0° C. to 5° C.). After dilution with water (50ml), the precipitate was filtered off with suction, washed with waterand dried in a drying cabinet. 7.1 g (76%) of the title compound wasobtained. LC/MS (Method LC10): RT=2.26 min; m/z=203.1 [M+H]⁺

b) 8-Bromo-6-chloro-9H-pyrido[3,4-b]indole

6-Chloro-9H-pyrido[3,4-b]indole (0.5 g, 2.09 mmol) was placed in water(10 ml) and 1 M hydrochloric acid (10 ml). N-Bromosuccinimide (0.37 g,2.09 mmol) was added in portions with exclusion of light. The mixturewas stirred at room temperature. After 1.5 days conversion to theproduct was complete, as shown by reaction monitoring by LC/MS. Theprecipitate was filtered off with suction, washed with water and driedin a drying cabinet to yield 642 mg of the title compound in the formits hydrochloride salt.

LC/MS (Method LC10): RT=2.16 min; m/z=281.0 [M+H]⁺

Intermediate 2.8-Bromo-6-chloro-9-cyclopropylmethyl-9H-pyrido[3,4-b]indole

a) 6-Chloro-9-cyclopropylmethyl-9H-pyrido[3,4-b]indole

6-Chloro-9H-pyrido[3,4-b]indole (2.0 g, 9.87 mmol) was placed in DMF (40ml) and treated with cesium carbonate (8.04 g, 24.68 mmol) andcyclopropylmethyl bromide (1.33 g, 0.965 ml, 9.87 mmol). The mixture wasstirred at room temperature overnight. The mixture was admixed withwater (20 ml) and extracted with EA (3×50 ml). The combined organicphases were washed with a saturated sodium chloride solution, dried overmagnesium sulfate and filtered, and the solvent was removed underreduced pressure. 2.5 g (99%) of the title compound was obtained. LC/MS(Method LC6): RT=0.93 min; m/z=257.2 [M+H]⁺

b) 8-Bromo-6-chloro-9-cyclopropylmethyl-9H-pyrido[3,4-b]indole

6-Chloro-9-(cyclopropylmethyl)-9H-pyrido[3,4-b]indole (0.5 g, 1.94 mmol)was placed in water (4.78 ml) and 1 M hydrochloric acid (4.78 ml).N-Bromosuccinimide (0.52 g, 2.92 mmol) was added in portions withexclusion of light. The mixture was stirred at room temperatureovernight. Further N-bromosuccinimide (0.52 g, 2.92 mmol) was added andthe mixture stirred at room temperature for 1 day, when reactionmonitoring showed complete conversion to the product. The mixture wasextracted with EA (3×20 ml), the combined organic phases were shakenwith saturated sodium chloride solution, the organic phase was driedover magnesium sulfate and filtered, and the solvent was removed underreduced pressure. 516 mg of crude product was obtained, which waspurified by preparative RP HPLC. The fractions containing the productwere combined and concentrated, and the residue freeze-dried to yield169 mg (19%) of the title compound in the form of its salt withtrifluoroacetic acid.

LC/MS (Method LC6): RT=1.21 min; m/z=334.9 [M+H]⁺

Intermediate 3. 8-Bromo-6-chloro-1-methyl-9H-pyrido[3,4-b]indole

a) 6-Chloro-1-methyl-9H-pyrido[3,4-b]indole

N-Chlorosuccinimide (1.92 g, 54.32 mmol) was added in portions withexclusion of light to a solution of harmane (2.50 g, 13.72 mmol) inwater (60 ml) and 1 M hydrochloric acid (60 ml). The mixture was stirredat room temperature overnight and subsequently for 2 h with cooling inice (0 to 5° C.). Reaction monitoring by LC/MS showed completeconversion to the product. The precipitate was filtered off withsuction, washed with water and dried at 50° C. in a drying cabinet togive 2.2 g (64%) of the title compound in the form of its hydrochloride.

LC/MS (Method LC10): RT=2.35 min; m/z=217.0 [M+H]⁺

b) 8-Bromo-6-chloro-1-methyl-9H-pyrido[3,4-b]indole

6-Chloro-1-methyl-9H-pyrido[3,4-b]indole hydrochloride (10.00 g, 39.51mmol) was placed in water (250 ml) and 1 M hydrochloric acid (250 ml).N-Bromosuccinimide (7.03 g, 39.51 mmol) was added in portions withexclusion of light. The mixture was stirred at room temperatureovernight. Further N-bromosuccinimide (0.52 g, 2.92 mmol) was added andthe mixture stirred at room temperature for 1 day. Reaction monitoringshowed complete conversion to the product, and a fine pale yellowprecipitate had formed. After cooling for 2 h in ice-water, theprecipitate was filtered off with suction and dried to constant weightat 45° C. under reduced pressure to give 13.00 g (99%) of the titlecompound in the form of its hydrochloride.

LC/MS (Method LC11): RT=2.52 min; m/z=295.1 [M+H]⁺

Intermediate 4.8-Bromo-6-chloro-9-cyclopropylmethyl-1-methyl-9H-pyrido[3,4-b]indole

8-Bromo-6-chloro-1-methyl-9H-pyrido[3,4-b]indole (4.22 g, 12.71 mmol)was placed in DMF (40 ml) and treated with cesium carbonate (10.35 g,31.78 mmol) and cyclopropylmethyl bromide (1.72 g, 12.71 mmol). Themixture was stirred at room temperature overnight. Reaction monitoringby LC/MS showed complete conversion to the product. The mixture wasadmixed with water (20 ml) and extracted with EA (3×50 ml). The combinedorganic phases were washed with saturated sodium chloride solution,dried over magnesium sulfate and filtered, and the solvent was removedunder reduced pressure. 4.2 g of crude product was obtained, which waspurified by preparative RP HPLC. The fractions containing the productwere pooled and concentrated, and the residue freeze-dried to yield 2.22g (50%) of the title compound in the form of its salt withtrifluoroacetic acid.

LC/MS (Method LC6): RT=1.13 min; m/z=349.0 [M+H]⁺

Intermediate 5. 6-Chloro-8-iodo-1-methyl-9H-pyrido[3,4-b]indole

a) 6-Chloro-8-iodo-1-methyl-9H-pyrido[3,4-b]indole

85% phosphoric acid (155 ml) was added to6-chloro-1-methyl-9H-pyrido[3,4-b]indole hydrochloride (13.1 g). Afterstirring for 30 min additional phosphoric acid (60 ml) was added. Aftercooling to 0° C. N-iodosuccinimide (12.8 g) was added in 3 portionswithin 6 h. After stirring for 16 h in the dark at room temperaturefurther N-iodosuccinimide (3.0 g) was added. After stirring for 24 h thereaction mixture was added to a stirred mixture of ice and water (600ml). After 30 min the precipitate was filtered off and washed withice-water. Then 10 N sodium hydroxide solution was added to the filtrateand the pH adjusted to 10. The newly formed precipitate was filtered offwith suction and combined with the first precipitate. Water was added tothe combined precipitates, and the pH adjusted to 9 with 10 N sodiumhydroxide solution. After stirring for 1 h, the solid was filtered offwith suction, treated with acetone (250 ml) and filtered off withsuction again. This procedure was repeated twice with diethyl ether, andthe obtained solid was dried in vacuo at 38° C. Then the solid wasdissolved in MeOH with addition of some DMF, and adsorbed to silica gel.After removal of the solvent the silica gel was given on top of aBüchner funnel filled with silica gel. The silica gel was first washedwith DCM to remove impurities, and then with a mixture of DCM and MeOH(20:1). The DCM/MeOH filtrate was concentrated in vacuo and the residuewas treated with diethyl ether containing some acetone. The solid wasfiltered off with suction and dried in vacuo to yield 10 g of the titlecompound.

LC/MS (Method LC13): RT=0.74 min; m/z=343.0 [M+H]⁺

Intermediate 6. 6-Chloro-9-ethyl-8-iodo-1-methyl-9H-pyrido[3,4-b]indole

b) 6-Chloro-9-ethyl-8-iodo-1-methyl-9H-pyrido[3,4-b]indole

6-chloro-8-iodo-1-methyl-9H-pyrido[3,4-b]indole (3.00 g, 8.76 mmol) wasdissolved in DMF (25 ml), and cesium carbonate (7.13 g, 21.89 mmol) andiodoethane (858 μl, 10.51 mmol) were added with stirring. After stirringfor 16 h under an argon atmosphere, water and DCM were added. Afterphase separation the aqueous phase was extracted 3 times with DCM. Thecombined organic layers were washed with brine, dried over sodiumsulfate and concentrated in vacuo. The residue was purified bychromatography over silica gel with DCM/MeOH (95:5) to yield 2.1 g ofthe title compound.

LC/MS (Method LC14): RT=0.87 min; m/z=371.1 [M+H]⁺

Intermediate 7. 6-Bromo-8-iodo-1-methyl-9H-pyrido[3,4-b]indole

a) 6-Bromo-1-methyl-9H-pyrido[3,4-b]indole

Harmane (2 g) was suspended in 2 M hydrochloric acid (60 ml) andN-bromosuccinimide (2.15 g) was added with stirring. After stirring for16 h the reaction mixture was set to pH 9 with 2 N sodium hydroxidesolution under cooling. Then EA was added, the phases were separated,and the aqueous phase was extracted 3 times with EA. The combinedorganic phases were dried over sodium sulfate, filtered and concentratedin vacuo. The residue was purified by chromatography over silica gelwith DCM/MeOH (gradient) to yield 1.69 g of the title compound.

LC/MS (Method LC4): RT=1.35 min; m/z=261.1 [M+H]⁺

b) 6-Bromo-8-iodo-1-methyl-9H-pyrido[3,4-b]indole

Phosphoric acid (25 ml) was added to6-chloro-1-methyl-9H-pyrido[3,4-b]indole (1.56 g), followed byN-iodosuccinimide (1.61 g). The mixture was stirred for 16 h at roomtemperature in the dark. Then the mixture was adjusted to pH 9 with 10 Msodium hydroxide solution under cooling. EA was added and the phaseswere separated, and the aqueous phase was extracted 3 times with EA. Thecombined organic phases were dried over sodium sulfate, filtered andconcentrated in vacuo. The residue was purified by chromatography oversilica gel with HEP/EA (1:0 to 0:1, gradient) to yield 1.39 g of thetitle compound.

LC/MS (Method LC8): RT=3.05 min; m/z=387.0 [M+H]⁺

Intermediate 8. 6-Bromo-9-ethyl-8-iodo-1-methyl-9H-pyrido[3,4-b]indole

6-Bromo-9-ethyl-8-iodo-1-methyl-9H-pyrido[3,4-b]indole

6-Bromo-8-iodo-1-methyl-9H-pyrido[3,4-b]indole (700 mg) was dissolved inDMF (10 ml), and cesium carbonate (1.47 g) and iodoethane (180 μl) wereadded with stirring. After stirring for 2 h under an argon atmosphereadditional iodoethane (180 μl) was added and stirring was continued foran additional 2 h. Then water and EA were added. The phases wereseparated, and the aqueous phase was extracted 3 times with EA. Thecombined organic phases were washed with brine, dried over sodiumsulfate, filtered and concentrated in vacuo. The residue was purified bychromatography over silica gel with HEP/EA (gradient)) to yield 650 mgof the title compound.

LC/MS (Method LC4): RT=1.65 min; m/z=415.0 [M+H]⁺

Intermediate 9. 6-Chloro-8-iodo-1,9-dimethyl-9H-pyrido[3,4-b]indole

6-Chloro-8-iodo-1-methyl-9H-pyrido[3,4-b]indole (1 g) was dissolved inDMF (10 ml), and cesium carbonate (2.38 g) and iodomethane (220 μl) wereadded with stirring.

After stirring for 16 h under argon atmosphere water and DCM were added.After phase separation, the aqueous phase was extracted 3 times withDCM. The combined organic phases were washed with brine, dried oversodium sulfate, filtered and concentrated in vacuo. The residue waspurified by chromatography over silica gel with DCM/MeOH (gradient) toyield 440 mg of the title compound.

LC/MS (Method LC5): RT=1.38 min; m/z=357.0 [M+H]⁺

Intermediate 10.8-Bromo-6-chloro-9-ethyl-1-methyl-9H-pyrido[3,4-b]indole

The title compound was synthesized from harmane analogously to thesynthesis of intermediates 3 and 4 using bromoethane.

LC/MS (Method LC12): RT=3.32 min; m/z=323.0 [M+H]⁺

Intermediate 11. 8-Bromo-6-chloro-9-ethyl-9H-pyrido[3,4-b]indole

The title compound was synthesized from norharmane analogously to thesynthesis of intermediates 3 and 4 using bromoethane.

LC/MS (Method LC10): RT=2.73 min; m/z=309.0 [M+H]⁺

Intermediate 12. 8-Bromo-6-chloro-1-isopropyl-9H-pyrido[3,4-b]indole

a) 1-Isopropyl-9H-pyrido[3,4-b]indole

A catalytic amount of palladium on charcoal (ca. 100 mg) was added to asolution of 1-isopropyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole (3.00g, 14 mmol) in xylene (20 ml) and the mixture was stirred at 150° C. for7 days. The catalyst was separated from the reaction mixture while hotby filtration through a silica gel layer, and the silica gel layer waswashed with a small amount of MeOH. The combined organic phases wereconcentrated and afforded 2.280 g (77%) of the title compound, which wasused in the next step without further purification.

LC/MS (Method LC6): RT=0.89 min; m/z=209.1 [M−H]⁻

b) 6-Chloro-1-isopropyl-9H-pyrido[3,4-b]indole

N-Chlorosuccinimide (1.74 g, 12.00 mmol) was added in portions withexclusion of light to a solution of 1-isopropyl-9H-pyrido[3,4-b]indole(2.28 g, 13.72 mmol) in 2 M hydrochloric acid (100 ml). The mixture wasstirred at room temperature overnight. Further N-chlorosuccinimide (0.5g, 3.82 mmol) was added in portions, and the mixture stirred for 1 day.Reaction monitoring by LC/MS showed complete conversion to the product.The mixture was diluted with water (200 ml), neutralized with conc.aqueous sodium hydroxide solution and shaken with EA. The organic phasewas separated, dried over magnesium sulfate and concentrated to give2.60 g (quantitative yield) of the title compound.

LC/MS (Method LC6): RT=0.98 min; m/z=245.1 [M+H]⁺

c) 8-Bromo-6-chloro-1-isopropyl-9H-pyrido[3,4-b]indole

N-Bromosuccinimide (2.73 g, 15.33 mmol) was added in portions withexclusion of light to a solution of6-chloro-1-isopropyl-9H-pyrido[3,4-b]indole (2.50 g, 10.22 mmol) in 2 Mhydrochloric acid (40 ml). The mixture was stirred at room temperatureovernight. Reaction monitoring by LC/MS showed complete conversion tothe product. The mixture was neutralized with 2 M aqueous sodiumhydroxide solution and shaken with EA. The organic phase was separated,dried over magnesium sulfate and concentrated to give 3.30 g(quantitative) of the crude title compound, which was used in the nextstep without further purification.

LC/MS (Method LC6): RT=1.06 min; m/z=323.0 [M+H]⁺

Intermediate 13. 8-Bromo-6-chloro-1-ethyl-9H-pyrido[3,4-b]indole

The title compound was synthesized from1-ethyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole analogously to thesynthesis of intermediate 12.

LC/MS (Method LC6): RT=1.04 min; m/z=309.0 [M+H]⁺

Intermediate 14. 8-Bromo-9-but-2-ynyl-6-chloro-9H-pyrido[3,4-b]indole

8-Bromo-6-chloro-9H-pyrido[3,4-b]indole (2.0 g, 7.1 mmol) in DMF (28 ml)was treated with cesium carbonate (5.79 g, 17.76 mmol) and1-bromo-but-2-yne (0.95 g, 7.1 mmol). The mixture was stirred at roomtemperature overnight. Reaction monitoring by LC/MS showed no conversionto the product. Two further additions of the 1-bromo-2-butyne compound,one equivalent each time, were made and the mixture was stirred overseveral days. The mixture was admixed with water (10 ml) and extractedwith EA (3×50 ml). The combined organic phases were washed withsaturated sodium chloride solution, dried over magnesium sulfate andfiltered, and the solvent was removed under reduced pressure. Theproduct was purified by preparative RP HPLC. The fractions containingthe product were pooled and concentrated, and the residue freeze-dried.809 mg (25%) of the title compound was obtained in the form of its saltwith trifluoroacetic acid.

LC/MS (Method LC8): RT=3.74 min; m/z=333.1 [M+H]⁺

Intermediate 15.8-Bromo-6-chloro-9-(2,2,2-trifluoroethyl)-9H-pyrido[3,4-b]indole

8-Bromo-6-chloro-9H-pyrido[3,4-b]indole (5.2 g, 21.75 mmol) in DMF (41ml) was treated with cesium carbonate (17.72 g, 54.38 mmol) and2,2,2-trifluoroethyl trifluoromethanesulfonate (5.30 g, 22.84 mmol). Themixture was stirred at room temperature overnight. Reaction monitoringby LC/MS showed complete conversion to the product. The mixture wasadmixed with water (20 ml) and extracted with EA (3×50 ml). The combinedorganic phases were washed with saturated sodium chloride solution,dried over magnesium sulfate and filtered, and the solvent was removedunder reduced pressure. The crude product was purified by preparative RPHPLC. The fractions containing the product were combined andconcentrated, and the residue freeze-dried. 1 g (13%) of the titlecompound were obtained in the form of its salt with trifluoroaceticacid.

LC/MS (Method LC2): RT=1.33 min; m/z=363.0 [M+H]⁺

Intermediate 16.8-Bromo-6-chloro-9-(2-methoxyethyl)-9H-pyrido[3,4-b]indole

8-Bromo-6-chloro-9H-pyrido[3,4-b]indole (1.0 g, 3.55 mmol) in DMF (10ml) was treated with cesium carbonate (3.4 g, 17.76 mmol) and2-bromoethyl methyl ether (0.59 g, 4.26 mmol). The mixture was treatedin an ultrasonic bath for 1 h and then stirred at room temperature for 3days. The solid was filtered off with suction, and the filtrate wasconcentrated. The crude product was purified by preparative RP HPLC. Thefractions containing the product were combined and concentrated, and theresidue freeze-dried. 0.56 g (35%) of the title compound was obtained inthe form of its salt with trifluoroacetic acid.

LC/MS (Method LC8): RT=3.14 min; m/z=339.0 [M+H]⁺

Intermediate 17. 6-Chloro-8-iodo-1,5-dimethyl-9H-pyrido[3,4-b]indole

a) 1,5-Dimethyl-9H-pyrido[3,4-b]indole

Water (150 ml) was added to 4-methyl-DL-tryptophan (1.5 g) at roomtemperature. Under ice cooling concentrated sulfuric acid (400 μl) andacetaldehyde (585 μl) were added. The mixture was heated to 65° C. for1.5 h. Then acetic acid (12 ml) was added and the first portion ofpotassium dichromate (30 mg). After heating to reflux additional 6portions of potassium dichromate (30 mg) were added until LC/MS controlshowed complete disappearance of the starting material. After cooling, asaturated sodium carbonate solution was added, followed by solid sodiumcarbonate to neutralise the solution. Then EA was added, the phases wereseparated and the aqueous phase was extracted twice with EA. Thecombined organic phases were dried over sodium sulfate, filtered andconcentrated in vacuo to yield 677 mg of the title compound.

LC/MS (Method LC5): RT=1.03 min; m/z=197.1 [M+H]⁺

b) 6-Chloro-1,5-dimethyl-9H-pyrido[3,4-b]indole

2 N HCl (30 ml) was added to 1,5-dimethyl-9H-pyrido[3,4-b]indole (677mg) under stirring at room temperature, followed by N-chlorosuccinimide(517 mg). Stirring was continued for 1 h. After standing overnight thepH of the reaction mixture was adjusted to pH 9 by 10 M sodium hydroxidesolution under ice cooling. Then EA was added, the phases were separatedand the aqueous phase was extracted twice with EA. The combined organicphases were dried over sodium sulfate, filtered and concentrated invacuo. The residue was purified by chromatography over silica gel withHEP/EA to yield 515 mg of the title compound.

LC/MS (Method LC5): RT=1.20 min; m/z=231.1 [M+H]⁺

c) 6-Chloro-8-iodo-1,5-dimethyl-9H-pyrido[3,4-b]indole

Phosphoric acid (18 ml) was added to6-chloro-1,5-dimethyl-9H-pyrido[3,4-b]indole (500 mg), followed byN-iodosuccinimide (512 mg), and the mixture stirred for 2.5 h at roomtemperature in the dark. Then further N-iodosuccinimide (51 mg) wasadded and stirring was continued for 20 h. The reaction mixture waspoured into ice water and the pH adjusted to 9 by 10 M sodium hydroxidesolution. The precipitate was filtered off with suction and EA added tothe filtrate. The phases were separated and the organic layer dried oversodium sulfate and concentrated in vacuo. The residue was purified bychromatography over silica gel with DCM/ethanol (gradient). Thefractions containing the product were combined and concentrated, and theresidue freeze-dried to yield 683 mg of the title compound.

LC/MS (Method LC5): RT=1.38 min; m/z=356.9 [M+H]⁺

Intermediate 18. 8-Bromo-1,6-dimethyl-9H-pyrido[3,4-b]indole

a) N-(2-(7-Bromo-5-methyl-1H-indol-3-yl)ethyl)acetamide

2-(7-Bromo-5-methyl-1H-indol-3-yl)ethylamine hydrochloride (3.6 g) wasconverted into the free base by treatment with 1 M sodium hydroxidesolution and DCM, separation of the phases, extraction of the aqueousphase with DCM, and drying of the combined DCM phases over sodiumsulfate, filtration and concentration in vacuo. The amine was suspendedin dry DCM (60 ml), and triethylamine (2.42 ml) was added. After coolingof the mixture to −40° C., acetyl chloride (1.03 ml) was added withstirring. After 30 min at −30° C. the reaction mixture was poured intoice water (100 ml). The DCM was removed in vacuo, and the remainingaqueous phase was extracted three times with EA. The combined EA phaseswere dried over sodium sulfate, filtrated and concentrated in vacuo toyield 4.74 g of the crude title compound.

LC/MS (Method LC5): RT=1.74 min; m/z=293.2 [M−H]⁻

b) 8-Bromo-1,6-dimethyl-4,9-dihydro-3H-pyrido[3,4-b]indole

N-(2-(7-Bromo-5-methyl-1H-indol-3-yl)ethyl)acetamide (4.27 g) wasdissolved in dry ACN (50 ml), and phosphorus oxychloride (6.62 ml) andphosphorus pentoxide (14.38 g) were added. After heating to 80° C. thereaction mixture was stirred at this temperature for 2 h. Then ice wasadded and the pH of the mixture was adjusted to 9 with 2 M sodiumhydroxide solution. This aqueous mixture was extracted with EA (threetimes), and the combined EA phases were dried, filtered and concentratedin vacuo. The residue was dissolved in DCM, and the organic phase wasextracted with a saturated sodium hydrogencarbonate solution, dried,filtered and concentrated in vacuo to yield 2.1 g of the title compound.The original aqueous phase was additionally extracted with DCM (threetimes), and the combined DCM phases were dried, filtered andconcentrated in vacuo to yield an additional 0.91 g of the titlecompound.

LC/MS (Method LC8): RT=2.81 min; m/z=277.1 [M+H]⁺

c) 8-Bromo-1,6-dimethyl-9H-pyrido[3,4-b]indole

8-Bromo-1,6-dimethyl-4,9-dihydro-3H-pyrido[3,4-b]indole (3 g) wassuspended in nitrobenzene (25 ml) and heated to 220° C. After 30 min thereaction mixture was cooled to room temperature and purified bychromatography over silica gel, first with HEP, then with DCM/MeOH 9:1.The fractions containing the product were combined and concentrated invacuo. The residue was subject to a further chromatography over silicagel with DCM/MeOH (gradient). The fractions containing the productcombined and concentrated in vacuo to yield 1 g of the title compound.

LC/MS (Method LC5): RT=1.44 min; m/z=275.1 [M+H]⁺

Intermediate 19. 8-Bromo-9-ethyl-1,6-dimethyl-9H-pyrido[3,4-b]indole

8-Bromo-1,6-dimethyl-9H-pyrido[3,4-b]indole (1 g) was dissolved in DMF(8 ml), and cesium carbonate (2.96 g) and iodoethane (350 μl) were addedwith stirring. After stirring for 3 h under an argon atmosphere, waterand EA were added. The phases were separated and the aqueous phase wasextracted 3 times with EA. The combined organic phases were washed withbrine, dried over sodium sulfate and concentrated in vacuo. The residuewas purified by chromatography over silica gel with DCM/MeOH to yield:740 mg of the title compound.

LC/MS (Method LC5): RT=1.59 min; m/z=303.2 [M+H]⁺

Intermediate 20. 6-Bromo-8-iodo-1,3-dimethyl-9H-pyrido[3,4-b]indole

a) 1-(1H-Indo)-3-yl)propan-2-one

Under argon 2-(1H-indol-3-yl)-N-methoxy-N-methylacetamide (3.00 g, 13.75mmol) was dissolved in THF (60 ml) and the solution cooled to 0° C. Amethylmagnesium bromide solution in THF (27.49 ml, 27.49 mmol) wasslowly added with stirring. After 2 h a second portion ofmethylmagnesium bromide solution (27.49 ml, 27.49 mmol) and after 3 h athird portion of methylmagnesium bromide solution (27.49 ml, 27.49 mmol)were added. Then an aqueous ammonium chloride solution was added,followed by EA. The phases were separated, and the organic phase waswashed with water and brine, dried, filtered and concentrated in vacuo.The residue was purified by chromatography over silica gel with HEP/EA(gradient) to yield 2.35 g of the title compound.

LC/MS (Method LC5): RT=1.56 min; m/z=174.1 [M+H]⁺

b) 1-(2-Acetyl-1H-indol-3-yl)propan-2-one

Under an argon atmosphere 1-(1H-indol-3-yl)propan-2-one (2.34 g, 13.5mmol) was dissolved in diethyl ether (35 ml). The solution was slowlyadded to zinc chloride (2.76 g, 20.26 mmol) in diethyl ether (50 ml)with stirring at 0° C. Stirring was continued for 30 min and then acetylchloride (1.92 ml, 27.02 mmol) was added. After stirring for 3 h, icewater was added, followed by an aqueous ammonium chloride solution andEA. The phases were separated, and the organic phase was washed withsaturated sodium hydrogencarbonate solution and brine, dried over sodiumsulfate, filtered and concentrated in vacuo. The residue was purified bychromatography over silica gel with DCM/MeOH (gradient) to yield 1.39 gof the title compound.

LC/MS (Method LC5): RT=1.58 min; m/z=216.1 [M+H]⁺

c) 1,3-Dimethyl-9H-pyrido[3,4-b]indole

1-(2-Acetyl-1H-indol-3-yl)propan-2-one (1.38 g, 6.41 mmol) was dissolvedin acetic acid (15 ml) and ammonium acetate (988 mg) was added. Afterstirring for 1 h at 60° C. the reaction mixture was cooled to 0° C. inan ice bath, the pH was set to 9 with 2 M sodium hydroxide solution, andthe mixture was extracted three times with DCM. The combined organicphases were dried over sodium sulfate, filtered and concentrated invacuo. The residue was purified by chromatography over silica gel withDCM/MeOH (gradient) to yield 810 mg of the title compound.

LC/MS (Method LC5): RT=1.06 min; m/z=197.1 [M+H]⁺

d) 6-Bromo-1,3-dimethyl-9H-pyrido[3,4-b]indole

2 N Hydrochloric acid (35 ml) was added to1,3-dimethyl-9H-pyrido[3,4-b]indole (812 mg, 4.14 mmol) under stirringat room temperature, followed by N-bromosuccinimide (810 mg, 4.55 mmol).Stirring was continued for 16 h. Then the pH of the reaction mixture wasadjusted to pH 9 with 10 M sodium hydroxide solution under ice cooling,EA was added, the phases were separated, and the aqueous phase wasextracted twice with EA. The combined organic phases were dried oversodium sulfate, filtered and concentrated in vacuo to yield 1.17 g ofthe title compound.

e) 6-Bromo-8-iodo-1,3-dimethyl-9H-pyrido[3,4-b]indole

Phosphoric acid (18 ml) was added to6-bromo-1,3-dimethyl-9H-pyrido[3,4-b]indole (1.14 g, 4.14 mmol),followed by N-iodosuccinimide (1.05 g, 4.56 mmol), and the reactionmixture stirred overnight at room temperature in the dark. Then themixture was poured into ice water and the pH adjusted to 9 with 10 Msodium hydroxide solution. The precipitate was filtered off withsuction, and EA was added to the filtrate. The phases were separated andthe aqueous layer was extracted three times with EA. The precipitate wasstirred with EA for 15 min, filtered off with suction and washed withfurther EA. The combined EA phases solutions were washed with brine,dried over sodium sulfate, filtered and concentrated in vacuo. Theresidue was purified by chromatography over silica gel with HEP/EA(gradient) to yield 480 mg of the title compound.

LC/MS (Method LC8): RT=3.25 min; m/z=400.9 [M+H]⁺

Intermediate 21.6-Bromo-9-ethyl-8-iodo-1,3-dimethyl-9H-pyrido[3,4-b]indole

6-Bromo-8-iodo-1,3-dimethyl-9H-pyrido[3,4-b]indole (475 mg, 1.18 mmol)was dissolved in DMF (5 ml), and cesium carbonate (965 mg) andiodoethane (114 μl) were added with stirring. After stirring for 16 hunder an argon atmosphere, water and DCM were added. The phases wereseparated, and the aqueous phase was extracted 3 times with DCM. Thecombined organic phases were washed with brine, dried over sodiumsulfate and concentrated in vacuo. The residue was purified bychromatography over silica gel with DCM/MeOH (gradient) to yield 470 mgof the title compound.

LC/MS (Method LC5): RT=1.66 min; m/z=428.9 [M+H]⁺

Intermediate 22.8-Bromo-6-chloro-9-(3-methyloxetan-3-ylmethyl)-9H-pyrido[3,4-b]indole

a) 2-Bromo-4-chloro-6-(3-fluoropyridin-4-yl)aniline

2,6-Dibromo-4-chloroaniline (6.5 g) was dissolved in a mixture of DME(180 ml) and water (60 ml). After addition of sodium carbonate (9.66 g)the flask was flushed with argon and the mixture was heated to reflux.3-Fluoro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (5.13g) and BDFP (1.86 g) were suspended in dry DMF (40 ml) and added to thereaction mixture via a syringe pump over 5 h. After 2 h further BDFP(0.186 g) was added separately to the reaction mixture. When theaddition was finished the mixture was cooled, filtered and concentratedin vacuo, and EA and a saturated sodium hydrogencarbonate solution wereadded to the residue. The phases were separated, the organic phase waswashed with brine, dried over sodium sulfate, filtered and concentratedin vacuo. The residue was purified by chromatography over silica gelwith HEP/EA (1:0 to 2:1). 2.02 g of the title compound was obtained.

LC/MS (Method LC5): RT=1.95 min; m/z=301.0 [M+H]⁺

b)2-Bromo-4-chloro-6-(3-fluoropyridin-4-yl)-N-(3-methyloxetan-3-ylmethyl)aniline

2-Bromo-4-chloro-6-(3-fluoropyridin-4-yl)aniline (500 mg) was dissolvedin DMF (10 ml), and cesium hydroxide (750 mg) was added. After flushingwith argon 3-bromomethyl-3-methyloxetane (330 mg) was added and thereaction mixture was stirred for 64 h at room temperature. Then asaturated sodium hydrogencarbonate solution and EA were added to themixture. The phases were separated and the aqueous phase was extractedthree times with EA. The combined organic phases were washed with brine,dried over sodium sulfate, filtered and concentrated in vacuo. Theresidue was purified by chromatography over silica gel with HEP/EA(gradient) to yield 284 mg of the title compound and 235 mg of8-bromo-6-chloro-9-(3-methyloxetan-3-ylmethyl)-9H-pyrido[3,4-b]indole(compound of step c)).

LC/MS (Method LC5): RT=2.04 min; m/z=385.1 [M+H]⁺

c) 8-Bromo-6-chloro-9-(3-methyloxetan-3-ylmethyl)-9H-pyrido[3,4-b]indole

2-Bromo-4-chloro-6-(3-fluoropyridin-4-yl)-N-(3-methyloxetan-3-ylmethyl)aniline(282 mg) was dissolved in THF (20 ml), flushed with argon, and a lithiumbis(trimethylsilyl)amide solution (0.73 ml, 0.73 mmol in THF) was addedwith stirring. After 2 h further lithium bis(trimethylsilyl)amidesolution (0.73 ml) was added, and stirring was continued for 16 h. Thena saturated ammonium chloride solution was added, followed by EA, andthe phases were separated. The organic phase was washed with a saturatedsodium hydrogencarbonate solution and brine, dried over sodium sulfate,filtered and concentrated in vacuo. The residue was purified bychromatography over silica gel with HEP/EA (gradient) to yield 176 mg ofthe title compound.

LC/MS (Method LC5): RT=1.63 min; m/z=365.1 [M+H]⁺

Exemplary Procedures for the Synthesis of Compounds of the Formula IExample 1. 6-Chloro-9-ethyl-8-pyridin-3-yl-9H-pyrido[3,4-b]indole

Tetrakis(triphenylphosphine)palladium(0) (40.45 mg) was added to asolution of 8-bromo-6-chloro-9-ethyl-pyrido[3,4-b]indole (0.31 g, 1mmol) in degassed toluene (5 ml) under an argon atmosphere in a 25 mltwo-necked flask with reflux condenser. The mixture was stirred for 10min at room temperature, then treated with a solution of3-pyridine-boronic acid (147.5 mg, 1.2 mmol) in ethanol and an aqueoussodium carbonate solution (2 M, 0.7 ml), and stirred for 8 h at 100° C.After addition of water (10 ml) the mixture was extracted with EA (3×20ml). The combined organic layers were washed with brine, dried overpotassium sulfate, filtered and concentrated in vacuo. The remainingsolid was treated with ACN/TFA (9:1) and an insoluble portion filteredoff. The filtrate was concentrated and the residue purified bypreparative RP HPLC. The fractions containing the product were combinedand lyophilized to yield 65 mg of the title compound in the form of itssalt with trifluoroacetic acid.

LC/MS (Method LC10): RT=2.15 min; m/z=308.0 [M+H]⁺

Example 2.6-Chloro-8-(1-(pyridin-3-ylmethyl)-1H-pyrazol-4-yl)-9-(2,2,2-trifluoroethyl)-9H-pyrido[3,4-b]indole

Degassed DME (25 ml) and degassed water (8 ml) were charged in a 25 mlmicrowave reaction flask under argon.8-Bromo-6-chloro-9-(2,2,2-trifluoroethyl)-9H-pyrido[3,4-b]indole (500mg, 1.38 mmol), sodium carbonate (583 mg, 5.50 mmol),1-pyridin-3-ylmethyl-1H-pyrazole-4-boronic acid pinacol ester (588 mg,2.06 mmol), and BDFP (224 mg, 0.28 mmol) were added, and the mixture wastreated in a microwave device at 130° C. for 11 min. The reactionmixture was concentrated and the residue purified by preparative RPHPLC. 510 mg (67%) of the title compound was obtained in the form of itssalt with trifluoroacetic acid.

LC/MS (Method LC3): RT=1.08 min; m/z=442.0 [M+H]⁺

Example 3.9-(But-2-ynyl)-6-chloro-8-(2,6-dichloropyridin-3-yl)-9H-pyrido[3,4-b]indole

8-Bromo-9-but-2-ynyl-6-chloro-pyrido[3,4-b]indole (385 mg, 0.86 mmol),cesium carbonate (560 mg, 1.72 mmol), 2,6-dichloropyridin-3-boronic acidpinacol ester (471 mg, 1.72 mmol) and BDFP (201 mg, 0.25 mmol) werereacted and the reaction mixture worked-up analogously as described forthe compound of example 47 to yield 84 mg (16%) of the title compound inthe form of its salt with trifluoroacetic acid.

LC/MS (Method LC12): RT=3.62 min; m/z=400.1 [M+H]⁺

Example 4.2-(6-Chloro-8-(2,6-dichloropyridin-3-yl)-9H-pyrido[3,4-b]indol-9-yl)acetonitrile

6-Chloro-8-(2,6-dichloropyridin-3-yl)-9H-pyrido[3,4-b]indole (324 mg,0.7 mmol) was placed in DMF (2 ml) and treated with potassium carbonate(242 mg, 1.75 mmol) and bromoacetonitrile (85 mg, 0.7 mmol). The mixturewas stirred at room temperature overnight, then admixed with water (5ml) and extracted with EA (3×10 ml). The combined organic phases werewashed with a saturated sodium chloride solution, dried over magnesiumsulfate and filtered, and the solvent was removed under reducedpressure. The crude product was purified by preparative RP HPLC. Thefractions containing the product were pooled, concentrated andfreeze-dried. 36 mg (10%) of the title compound was obtained in the formof its salt with trifluoroacetic acid.

LC/MS (Method LC6): RT=0.99 min; m/z=387.1 [M+H]⁺

Example 5.6-Bromo-9-ethyl-1-methyl-8-(1-pyridin-3-ylmethyl-1H-pyrazol-4-yl)-9H-pyrido[3,4-b]indole

6-Bromo-9-ethyl-8-iodo-1-methyl-9H-pyrido[3,4-b]indole (200 mg) wasdissolved in DME (6 ml) and water (2 ml) in a microwave vessel, andsodium carbonate (204 mg),3-((4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl)methyl)pyridine(137 mg) and BDFP (79 mg) were added. The mixture was treated for 10 minat 100° C. in a microwave oven. Then further3-((4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl)methyl)pyridine(69 mg) was added and the mixture again treated for 10 min at 100° C. ina microwave oven. After cooling the mixture was filtered and thefiltrate concentrated in vacuo. After addition of a saturated sodiumhydrogencarbonate solution the mixture was extracted three times withDCM. The combined organic phases were dried over sodium sulfate,filtered and concentrated in vacuo. After preparative RP HPLC thefractions containing the product were combined and lyophilized. 145 mgof the title compound were obtained in the form of its salt withtrifluoroacetic acid. After addition of a saturated sodiumhydrogencarbonate solution to 60 mg of this salt the mixture wasextracted three times with DCM. The combined organic phases were driedover sodium sulfate, filtered and concentrated in vacuo. The residue wastreated with water and some ACN added. After lyophilization 48 mg of thetitle compound were obtained.

LC/MS (Method LC5): RT=1.27 min; m/z=446.2 [M+H]⁺

Examples 6 and 7.6-Chloro-9-ethyl-1-methyl-8-[1-(2-methyl-pyridin-3-ylmethyl)-2H-pyrazol-3-yl]-9H-pyrido[3,4-b]indoleand6-chloro-9-ethyl-1-methyl-8-[2-(2-methyl-pyridin-3-ylmethyl)-1H-pyrazol-3-yl]-9H-pyrido[3,4-b]indole

6-Chloro-9-ethyl-1-methyl-8-(1H-pyrazol-3-yl)-9H-pyrido[3,4-b]indole(150 mg) was dissolved in dry DMF (3 ml) in a microwave vessel andcesium carbonate (470 mg) and 3-(bromomethyl)-2-methylpyridinehydrochloride (161 mg) were added with stirring. After treating thismixture for 1 h at 100° C. in a microwave oven the mixture was cooledand further 3-(bromomethyl)-2-methylpyridine hydrochloride (54 mg) wasadded. After further 1.5 h at 100° C. in the microwave oven the mixturewas cooled, filtered and concentrated in vacuo. After addition of asaturated sodium hydrogencarbonate solution the mixture was extractedfour times with DCM. The combined organic phases were dried over sodiumsulfate, filtered and concentrated in vacuo. After preparative RP HPLCthe fractions containing each of the two isomeric products were combinedand lyophilized.

Example 6.6-Chloro-9-ethyl-1-methyl-8-[1-(2-methyl-pyridin-3-ylmethyl)-1H-pyrazol-3-yl]-9H-pyrido[3,4-b]indole

91 mg of the title compound were obtained in the form of its salt withtrifluoroacetic acid, of which 60 mg were treated with sodiumhydrogencarbonate as described in example 5 to yield 41 mg of the freebase.

LC/MS (Method LC4): RT=1.16 min; m/z=416.2 [M+H]⁺

Example 7.6-Chloro-9-ethyl-1-methyl-8-[2-(2-methyl-pyridin-3-ylmethyl)-2H-pyrazol-3-yl]-9H-pyrido[3,4-b]indole

69 mg of the title compound were obtained in the form of its salt withtrifluoroacetic acid, of which 51 mg were treated with sodiumhydrogencarbonate as described in example 5 to yield 24 mg of the freebase.

LC/MS (Method LC4): RT=1.16 min; m/z=416.2 [M+H]⁺

Example 8.6-Chloro-1,5-dimethyl-8-[4-(3-methyl-oxetan-3-ylmethoxy)-phenyl]-9H-pyrido[3,4-b]indole

The title compound was synthesized analogously to the synthesis of thecompound of example 27 in two microwave vessels. 170 mg of6-chloro-8-iodo-1,5-dimethyl-9H-pyrido[3,4-b]indole and 116 mg of4-(3-methyloxetan-3-ylmethoxy)-phenylboronic acid were used in each run.The reaction mixture was treated for 10 min at 100° C. in a microwaveoven. After HPLC purification the fractions containing the product werecombined and concentrated to remove the ACN, and then neutralised with asaturated sodium hydrogencarbonate solution. The mixture was extractedtwice with EA and the combined organic phases were dried over sodiumsulfate, filtered and concentrated in vacuo. The residue was treatedwith ethanol and water to form a milky suspension which was stirred for1 h. Then the slurry was concentrated in vacuo and dried in high vacuumovernight. 190 mg of the title compound was obtained.

LC/MS (Method LC5): RT=1.56 min; m/z=407.1 [M+H]⁺

Example 9.6-Chloro-8-(2,5-dimethyl-2H-pyrazol-3-yl)-9-ethyl-1-methyl-9H-pyrido[3,4-b]indole

6-Chloro-9-ethyl-8-iodo-1-methyl-9H-pyrido[3,4-b]indole (320 mg) wasdissolved in a mixture of DME (9 ml) and water (3 ml). After addition ofsodium carbonate (370 mg) the reaction mixture was flushed with argon.After heating to reflux,1,3-dimethyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole(192 mg) and BDFP (70 mg) in dry DMF (3 ml) were added to the reactionmixture via a syringe pump over 4 h. After 1 h an extra portion of 7 mgof BDFP was added to the reaction mixture. When the addition via thesyringe pump was finished, the mixture was cooled, filtered andconcentrated in vacuo. The crude product was first purified bychromatography over silica gel with DCM/MeOH (gradient) and then bypreparative RP HPLC. The fractions containing the product were combinedand lyophilized. 187 mg of the title compound were obtained in the formof its salt with trifluoroacetic acid. After addition of a saturatedsodium hydrogencarbonate solution to 157 mg of this salt the mixture wasextracted three times with DCM. The combined organic layers were driedover sodium sulfate, filtered and concentrated in vacuo to yield 80 mgof the title compound.

LC/MS (Method LC5): RT=1.40 min; m/z=339.2 [M+H]⁺

Example 10.2-(4-[6-Chloro-9-(2,2,2-trifluoroethyl)-9H-pyrido[3,4-b]indol-8-yl]pyrazol-1-yl)ethanol

2-(4-(6-Chloro-9-(2,2,2-trifluoroethyl)-9H-pyrido[3,4-b]indol-8-yl)-pyrazol-1-yl]-ethylacetate (238.1 mg, 0.55 mmol) was dissolved in MeOH (4 ml) and 2equivalents of sodium methoxide (25% solution in MeOH) was added. Thereaction mixture was stirred for 2 h at room temperature. The solventwas removed in vacuo and the residue was purified by HPLC. The obtainedproduct was dissolved in EA, washed with a saturated sodiumhydrogencarbonate solution, and the organic phase was dried andconcentrated in vacuo. The residue was recrystallized from HEP/EA toyield 72.5 mg of the title compound.

LC/MS (Method LC4): RT=1.32 min; m/z=395.3 [M+H]⁺

Example 11.6-Chloro-8-(1-phenyl-1H-pyrazol-4-yl)-9-(2,2,2-trifluoroethyl)-9H-pyrido[3,4-b]indole

6-Chloro-8-(1H-pyrazol-4-yl)-9-(2,2,2-trifluoroethyl)-9H-pyrido[3,4-b]indole(130 mg) was dissolved in dry DMF (10 ml), phenylboronic acid (68 mg),copper(II) acetate (76 mg) and pyridine (66 mg) were added and theresulting mixture was stirred for 2 h. After standing overnight at roomtemperature the mixture was filtered and concentrated in vacuo. Theresidue was purified by RP HPLC. The fractions containing the productwere combined and lyophilized. 41 mg of the title compound were obtainedin the form of its salt with trifluoroacetic acid.

LC/MS (Method LC4): RT=1.77 min; m/z=427.2 [M+H]⁺

Example 12. tert-Butyl4-(6-chloro-9-(2,2,2-trifluoroethyl)-9H-pyrido[3,4-b]indol-8-yl)-1H-pyrazole-1-carboxylate

6-Chloro-8-(1H-pyrazol-4-yl)-9-(2,2,2-trifluoroethyl)-9H-pyrido[3,4-b]indole(94.0 mg, 0.27 mmol) was dissolved in dry DCM (5 ml) andN-ethyl-diisopropylamine (34.64 mg, 0.27 mmol, 50.0 μl), di-tert-butyldicarbonate (58.49 mg, 0.27 mmol) and 4-dimethylaminopyridine (3.27 mg,30.0 μmol) were added. The reaction mixture was stirred 2 h at roomtemperature. Then additional 0.5 equivalents each ofN-ethyl-diisopropylamine, di-tert-butyl dicarbonate and4-dimethylaminopyridine were added, and the reaction mixture was stirredovernight at room temperature. To the reaction mixture water was added,the organic phase was separated, dried, and the solvent was removed invacuo. The residue was purified by MPLC with HEP/EA. 68.0 mg of thetitle compound were obtained.

LC/MS (Method LC6): RT=1.24 min; m/z=451.0 [M+H]⁺

Example 13.6-Chloro-1-methyl-8-[4-(2-(1H-pyrazol-1-yl)ethoxy)-phenyl]-9H-pyrido[3,4-b]indole

A microwave reaction vessel was charged with6-chloro-8-iodo-1-methyl-9H-pyrido[3,4-b]indole (250 mg), sodiumcarbonate (310 mg), 4-[2-(1H-pyrazol-1-yl)ethoxy]-benzeneboronic acidpinacol ester (229 mg), BDFP (119 mg), DME (7.5 ml) and water (2.5 ml).After 10 min at 100° C. in a microwave oven the reaction mixture wasfiltered and a saturated solution of sodium hydrogencarbonate and DCMwere added to the filtrate. After phase separation the aqueous phase wasextracted twice with DCM. The combined DCM phases were dried over sodiumsulphate, filtered and concentrated in vacuo. The residue was purifiedby RP HPLC. The fractions containing the product were combined, the ACNwas removed in vacuo and the remaining aqueous solution was lyophilized.The residue was treated with a saturated solution of sodiumhydrogencarbonate and DCM. After phase separation the aqueous phase wasextracted twice with DCM. The combined DCM phases were dried over sodiumsulphate, filtered and concentrated in vacuo to yield 207 mg of thetitle compound.

LC/MS (Method LC5): RT=1.63 min; m/z=403.2 [M+H]⁺

Example 14. 8-(4-Methoxy-phenyl)-1,6-dimethyl-9H-pyrido[3,4-b]indole

8-Bromo-1,6-dimethyl-9H-pyrido[3,4-b]indole (200 mg) was dissolved in amixture of DME (9 ml) and water (3 ml). After addition of sodiumcarbonate (310 mg) the reaction mixture was flushed with argon. Afterheating to reflux a mixture of 4-methoxyphenylboronic acid pinacol ester(255 mg) and BDFP (119 mg) in dry DMF (4 ml) were given to the reactionmixture via a syringe pump over 3 h. After 1 h an extra portion of 59 mgof BDFP was added to the reaction mixture. When the addition via thesyringe pump was finished, the mixture was cooled, filtered andconcentrated in vacuo. The crude product was dissolved in EA, and the EAphase was washed with a saturated sodium hydrogencarbonate solution,dried, filtered and concentrated in vacuo. The residue was purified by apreparative RP HPLC. The fractions containing the product were combinedand lyophilized. 30 mg of the title compound were obtained in the formof its salt with trifluoroacetic acid.

LC/MS (Method LC5): RT=1.63 min; m/z=303.2 [M+H]⁺

Example 15.9-Ethyl-1,6-dimethyl-8-(1-methyl-1H-pyrazol-4-yl)-9H-pyrido[3,4-b]indole

A microwave reaction vessel was charged with8-bromo-9-ethyl-1,6-dimethyl-9H-pyrido[3,4-b]indole (200 mg), sodiumcarbonate (280 mg),1-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole(206 mg), BDFP (108 mg), DME (9 ml) and water (3 ml). After 12 min at130° C. in a microwave oven the mixture was filtered and the filtrateconcentrated in vacuo. The residue was dissolved in EA. The resultingsolution was washed with a saturated sodium hydrogencarbonate solution,dried over sodium sulfate, filtered and concentrated in vacuo. Theresidue was purified by preparative RP HPLC. The fractions containingthe product were combined and lyophilized. 7 mg of the title compoundwere obtained in the form of its salt with trifluoroacetic acid.

LC/MS (Method LC5): RT=1.43 min; m/z=305.2 [M+H]⁺

Example 16.6-Bromo-1,3-dimethyl-8-[4-(2-pyrazol-1-yl-ethoxy)-phenyl]-9H-pyrido[3,4-b]indole

A microwave reaction vessel was charged with6-bromo-8-iodo-1,3-dimethyl-9H-pyrido[3,4-b]indole (200 mg),1-(2-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenoxy)ethyl)-1H-pyrazole(157 mg), BDFP (81 mg), sodium carbonate (211 mg), DME (6 ml) and water(2 ml). After 10 min at 100° C. in a microwave oven the mixture wascooled and a saturated sodium hydrogencarbonate solution followed by DCMwas added. The phases were separated and the organic phase was driedover sodium sulfate, filtered and concentrated in vacuo. The residue waspurified by preparative RP HPLC. The fractions containing the productwere combined and lyophilized. 162 mg of the title compound was obtainedin the form of its salt with trifluoroacetic acid.

LC/MS (Method LC5): RT=1.67 min; m/z=461.2 [M+H]⁺

Example 17.6-(6-Chloro-9-ethyl-1-methyl-9H-pyrido[3,4-b]indol-8-yl)-3-methoxy-pyridin-2-ylamine

A microwave reaction vessel was charged with6-chloro-9-ethyl-8-iodo-1-methyl-9H-pyrido[3,4-b]indole (250 mg),6-amino-5-methoxypyridin-2-ylboronic acid (860 mg), BDFP (111 mg),sodium carbonate (71 mg), DME (6 ml) and water (2 ml). After 10 min at100° C. in a microwave oven the mixture was cooled and filtered. 1 Nhydrochloric acid was added to the filtrate, which was washed twice withDCM. The aqueous phase was set to pH 9 with 1 N sodium hydroxidesolution and extracted three times with DCM. The combined organic phaseswere dried over sodium sulfate, filtered and concentrated in vacuo. Theresidue was purified by preparative RP HPLC. The fractions containingthe product were combined, the ACN was removed in vacuo and the aqueousresidue lyophilized to yield 50 mg of the title compound in the form ofits salt with trifluoroacetic acid.

LC/MS (Method LC5): RT=1.42 min; m/z=367.2 [M+H]⁺

Example 18.6-Chloro-9-ethyl-1-methyl-8-(3-phenyl-isoxazol-5-yl)-9H-pyrido[3,4-b]indole

A microwave reaction vessel was charged with6-chloro-9-ethyl-8-iodo-1-methyl-9H-pyrido[3,4-b]indole (200 mg),3-phenyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)isoxazole (176mg), BDFP (89 mg), sodium carbonate (286 mg), DME (8 ml) and water (3ml). After 15 min at 100° C. in a microwave oven the mixture was cooled,filtered, and a saturated sodium hydrogencarbonate solution followed byDCM were added to the filtrate. The phases were separated and theaqueous phase was extracted three times with DCM. The combined organicphases were dried over sodium sulfate, filtered and concentrated invacuo. The residue was purified by preparative RP HPLC. The fractionscontaining the product were combined, the ACN was removed in vacuo andthe remaining aqueous solution was lyophilized to yield 178 mg of thetitle compound in the form of its salt with trifluoroacetic acid. 135 mgof this salt was treated with a saturated sodium hydrogencarbonatesolution and DCM. The phases were separated and the aqueous phase wasextracted twice with DCM. The combined organic phases were dried oversodium sulfate, filtered and concentrated in vacuo. The residue wastreated with water, filtered off with suction and dried in high vacuumat 40° C. to yield 106 mg of the title compound. LC/MS (Method LC8):RT=3.79 min; m/z=388.1 [M+H]⁺

Examples 19 and 20.6-Chloro-9-ethyl-1-methyl-8-(2-methyl-2H-pyrazol-3-yl)-9H-pyrido[3,4-b]indoleand6-chloro-9-ethyl-1-methyl-8-(1-methyl-1H-pyrazol-3-yl)-9H-pyrido[3,4-b]indole

6-Chloro-9-ethyl-1-methyl-8-(1H-pyrazol-3-yl)-9H-pyrido[3,4-b]indole (95mg) was dissolved in dry DMF (3 ml), and sodium hydride (15 mg) wasadded with stirring. After stirring for 30 min, iodomethane (48 mg) wasadded and stirring was continued for an additional 16 h. Then EA wasadded and the solution was washed with water and brine. The organicphase was dried over sodium sulfate, filtered and concentrated in vacuo.The residue was purified by preparative RP HPLC. The fractionscontaining each of the two isomeric products were combined, the ACN wasremoved in vacuo, the aqueous residues were set basic with a saturatedhydrogencarbonate solution and extracted three times with DCM. Thecombined organic phases were dried over sodium sulfate, filtered,concentrated in vacuo, and the residue dissolved in water/ACN andlyophilized.

Example 19.6-Chloro-9-ethyl-1-methyl-8-(2-methyl-2H-pyrazol-3-yl)-9H-pyrido[3,4-b]indole

20 mg of the title compound, the more polar of the two isomers, wereobtained. LC/MS (Method LC4): RT=1.30 min; m/z=325.2 [M+H]⁺

Example 20.6-Chloro-9-ethyl-1-methyl-8-(1-methyl-1H-pyrazol-3-yl)-9H-pyrido[3,4-b]indole

32 mg of the title compound, the less polar of the two isomers, wasobtained. LC/MS (Method LC4): RT=1.32 min; m/z=325.2 [M+H]⁺

Example 21.6-Bromo-9-ethyl-1,3-dimethyl-8-(1-methyl-1H-pyrazol-4-yl)-9H-pyrido[3,4-b]indole

In a microwave reaction vessel (20 ml)6-bromo-9-ethyl-8-iodo-1,3-dimethyl-9H-pyrido[3,4-b]indole (465 mg, 1.08mmol) was dissolved in a mixture of DME (12 ml) and water (4 ml). Then1-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole(225.48 mg, 1.08 mmol), sodium carbonate (459.43 mg, 4.33 mmol) and BDFP(177 mg) were added and the mixture was treated for 10 min at 100° C. ina microwave oven. Then further1-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole(112 mg) and BDFP (89 mg) were added and the mixture was heated for 12min at 120° C., followed by additional 15 min at 130° C., in a microwaveoven. After cooling a saturated sodium hydrogencarbonate solution andDCM were added and the phases were separated. The organic phase wasdried over sodium sulfate, filtered and concentrated in vacuo. Theresidue was purified by preparative RP HPLC. The fractions containingthe product were combined and lyophilized to yield 280 mg of the titlecompound in the form of its salt with trifluoroacetic acid. LC/MS(Method LC5): RT=1.52 min; m/z=383.1 [M+H]⁺

Example 22.6-Chloro-8-(4-methoxy-phenyl)-1,9-dimethyl-9H-pyrido[3,4-b]indole

In a microwave reaction vessel (10 ml)6-chloro-8-iodo-1,9-dimethyl-9H-pyrido[3,4-b]indole (200 mg, 561 μmol)was dissolved in a mixture of DME (6 ml) and water (2 ml). Then2-(4-methoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (131 mg, 561μmol), sodium carbonate (238 mg, 2.24 mmol) and BDFP (92 mg, 110 μmol)were added, and the mixture was treated for 10 min at 100° C. and thenfor 15 min at 120° C. in a microwave oven. After cooling, a sodiumhydrogencarbonate solution and DCM were added and the phases wereseparated. The aqueous phase was extracted three times with DCM. Thecombined organic phases were dried over sodium sulfate, filtered andconcentrated in vacuo. The residue was purified by preparative RP HPLC.The fractions containing the product were combined and lyophilized. 47mg of the title compound in the form of its salt with trifluoroaceticacid was obtained.

LC/MS (Method LC4): RT=1.52 min; m/z=337.2 [M+H]⁺

Example 23.6-Chloro-1-methyl-8-(2-methyl-2,3-dihydro-benzofuran-5-yl)-9H-pyrido[3,4-b]indole

In a microwave reaction vessel (10 ml)6-chloro-8-iodo-1-methyl-9H-pyrido[3,4-b]indole (200 mg, 580 μmol) wasdissolved in a mixture of DME (6 ml) and water (2 ml). Then2-methyl-2,3-dihydrobenzofuran-5-ylboronic acid (103.92 mg, 583.83μmol), sodium carbonate (248 mg) and BDFP (95 mg) were added and themixture was treated for 10 min at 100° C. in a microwave oven. Aftercooling, a saturated sodium hydrogencarbonate solution and DCM wereadded and the phases were separated. The aqueous phase was extractedthree times with DCM. The combined organic phases were dried over sodiumsulfate, filtered and concentrated in vacuo. The residue was purified bypreparative RP HPLC. The fractions containing the product were combinedand lyophilized to yield 120 mg of the title compound in the form of itssalt with trifluoroacetic acid. 88 mg of this salt were treated with asaturated sodium hydrogencarbonate solution and DCM. The aqueous phasewas removed by means of a Chem Elut cartridge, and the organic phase wasconcentrated in vacuo to yield 52 mg of the title compound.

LC/MS (Method LC4): RT=1.56 min; m/z=349.2 [M+H]⁺

Example 24.[4-(6-Chloro-1-methyl-9H-pyrido[3,4-b]indol-8-yl)-phenyl]-phenyl-methanol

Under an argon atmosphere4-(6-chloro-1-methyl-9H-pyrido[3,4-b]indol-8-yl)-benzaldehyde (60 mg)was dissolved in in dry THF with stirring. The solution was cooled to 0°C. and a phenyl magnesium bromide solution (0.41 ml; 1 M in THF) wasadded with stirring. After the addition was complete the ice bath wasremoved. After 20 h water was added, and the aqueous phase was extractedthree times with EA. The combined organic phases were dried over sodiumsulfate, filtered and concentrated in vacuo. The residue was purified bychromatography over silica gel with DCM/MeOH (gradient). The fractionscontaining the product were combined and concentrated in vacuo to yield38 mg of the title compound.

LC/MS (Method LC4): RT=1.54 min; m/z=399.2 [M+H]⁺

Example 25.6-Chloro-1,9-dimethyl-8-(1-methyl-1H-pyrazol-4-yl)-9H-pyrido[3,4-b]indole

In a microwave reaction vessel (10 ml)6-chloro-8-iodo-1,9-dimethyl-9H-pyri do[3,4-b]indole (206 mg, 577 μmol)was dissolved in a mixture of DME (6 ml) and water (2 ml). Then1-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole(120 mg, 577.70 μmol), sodium carbonate (244.92 mg, 2.31 mmol) and BDFP94 mg were added and the mixture was treated for 15 min at 120° C. in amicrowave oven. To complete the conversion, the mixture was treated foranother 15 min at 120° C. in a microwave oven. After cooling, a sodiumhydrogencarbonate solution and DCM were added and the phases wereseparated. The aqueous phase was extracted three times with DCM. Thecombined organic phases were dried over sodium sulfate, filtered andconcentrated in vacuo. The residue was purified by preparative RP HPLC.The fractions containing the product were combined and lyophilized. Theobtained product was further purified by another preparative RP HPLC,followed by chromatography over silica gel with DCM/MeOH (gradient), toyield 12 mg of the title compound.

LC/MS (Method LC4): RT=1.24 min; m/z=311.2 [M+H]⁺

Example 26.(2-[4-(6-Chloro-9-ethyl-1-methyl-9H-pyrido[3,4-b]indol-8-yl)-phenoxy]-ethyl)-diisopropyl-amine

a)8-(4-(2-Bromoethoxy)phenyl)-6-chloro-9-ethyl-1-methyl-9H-pyrido[3,4-b]indole

The title compound was synthesized analogously to the synthesis of thecompound of example 31, using 4-(2-bromoethoxy)phenylboronic acid.

LC/MS (Method LC8): RT=3.89 min; m/z=443.2 [M+H]⁺

b)(2-[4-(6-Chloro-9-ethyl-1-methyl-9H-pyrido[3,4-b]indol-8-yl)-phenoxy]-ethyl)-diisopropyl-amine

In a microwave vessel8-(4-(2-bromoethoxy)phenyl)-6-chloro-9-ethyl-1-methyl-9H-pyrido[3,4-b]indole(70 mg) was dissolved in diisopropylamine (3 ml). The mixture wastreated for 10 h at 100° C. in a microwave oven. After cooling the aminewas removed in vacuo and the residue was purified by chromatography oversilica gel with DCM/MeOH (gradient). The fractions containing theproduct were combined and concentrated in vacuo. The residue wasdissolved in a mixture of ACN and water containing 0.05% hydrogenchloride, and the solution lyophilized. 14 mg of the title compound wasobtained in the form of(2-[4-(6-chloro-9-ethyl-1-methyl-9H-pyrido[3,4-b]indol-8-yl)-phenoxy]-ethyl)-diisopropyl-aminedihydrochloride.

LC/MS (Method LC8): RT=2.74 min; m/z=464.3 [M+H]⁺

Example 27.6-Chloro-8-(4-methoxy-phenyl)-1,5-dimethyl-9H-pyrido[3,4-b]indole

In a microwave reaction vessel (10 ml)6-chloro-8-iodo-1,5-dimethyl-9H-pyri do[3,4-b]indole (180 mg, 504.78μmol) was dissolved in a mixture of DME (6 ml) and water (2 ml). Then2-(4-methoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (118.17 mg,504.78 μmol), sodium carbonate (214.00 mg, 2.02 mmol) and BDFP (82.44mg, 100.96 μmol) were added, and the mixture was treated for 15 min at120° C. in a microwave oven. After cooling, a sodium hydrogencarbonatesolution and DCM were added and the phases were separated. The aqueousphase was extracted three times with DCM. The combined organic phaseswere dried over sodium sulfate, filtered and concentrated in vacuo. Theresidue was purified by preparative RP HPLC. The fractions containingthe product were combined and lyophilised. 92 mg of the title compoundin the form of its salt with trifluoroacetic acid was obtained.

LC/MS (Method LC4): RT=1.56 min; m/z=337.2 [M+H]⁺

Example 28.6-Chloro-9-ethyl-1-methyl-8-[4-(2-morpholin-4-yl-ethoxy)-phenyl]-9H-pyrido[3,4-b]indole

In a microwave vessel8-(4-(2-bromoethoxy)phenyl)-6-chloro-9-ethyl-1-methyl-9H-pyrido[3,4-b]indole(31 mg) was dissolved in morpholine (2 ml). The mixture was treated for15 min at 100° C. in a microwave oven. After cooling the amine wasremoved in vacuo and the residue was purified by chromatography oversilica gel with DCM/MeOH (gradient). The fractions containing theproduct were combined and concentrated in vacuo. The residue wasdissolved in a mixture of ACN and water containing 0.05% hydrochloricacid and lyophilized. 25 mg of the title compound in the form of6-chloro-9-ethyl-1-methyl-8-[4-(2-morpholin-4-yl-ethoxy)-phenyl]-9H-pyrido[3,4-b]indoledihydrochloride was obtained.

LC/MS (Method LC8): RT=2.48 min; m/z=450.3 [M+H]⁺

Example 29.[4-(6-Chloro-1-methyl-9H-pyrido[3,4-b]indol-8-yl)-benzyl]-cyclopentyl-amine

4-(6-Chloro-1-methyl-9H-pyrido[3,4-b]indol-8-yl)benzylamine (80 mg) wasdissolved in DME (2 ml) and acetic acid (0.250 ml). After the additionof cyclopentanone (127 mg) the reaction mixture war stirred for 15 minat room temperature. Then sodium triacetoxyborohydride (111 mg) wasadded. After stirring for 2 h, DCM was added to the reaction mixture andthe solution washed with a saturated sodium hydrogencarbonate solutionand brine. The organic phase was dried over sodium sulfate, filtered andconcentrated in vacuo. The residue was purified by preparative RP HPLC.The fractions containing the product were combined, the ACN was removedin vacuo and the residue was lyophilized to yield 88 mg of the titlecompound in the form of its salt with trifluoroacetic acid. 65 mg ofthis salt was treated a with saturated sodium hydrogencarbonate solutionand EA. The phases were separated, and the aqueous phase was extractedtwice with EA. The combined organic phases were dried over sodiumsulfate, filtered and concentrated in vacuo to yield 44 mg of the titlecompound.

LC/MS (Method LC4): RT=1.15 min; m/z=390.2 [M+H]⁺

Example 30.6-Chloro-9-ethyl-1-methyl-8-(4-morpholin-4-ylmethyl-phenyl)-9H-pyrido[3,4-b]indole

4-(6-Chloro-9-ethyl-1-methyl-9H-pyrido[3,4-b]indol-8-yl)benzaldehyde (94mg) was dissolved in DME (2 ml) and acetic acid (0.16 ml). Afteraddition of morpholine (28 mg) the reaction mixture was stirred for 15min at room temperature. Then sodium triacetoxyborohydride (144 mg) wasadded. After stirring for 16 h, DCM was added to the reaction mixture,the solution washed with a saturated sodium hydrogencarbonate solutionand brine. The organic phase was dried over sodium sulfate, filtered andconcentrated in vacuo. The residue was purified by preparative RP HPLC.The fractions containing the product were combined, the ACN was removedin vacuo and the residue was lyophilised to yield 45 mg of the titlecompound in the form of its salt with trifluoroacetic acid.

LC/MS (Method LC4): RT=1.07 min; m/z=420.3 [M+H]⁺

Example 31. 4-(6-Chloro-1-methyl-9H-pyrido[3,4-b]indol-8-yl)benzaldehyde

In a microwave reaction vessel (10 ml)6-chloro-8-iodo-1-methyl-9H-pyrido[3,4-b]indole (150 mg) was dissolvedin a mixture of DME (5 ml) and water (1.5 ml). Then4-formylphenylboronic acid (66 mg), sodium carbonate (185 mg) and BDFP(72 mg) were added and the mixture was treated for 10 min at 100° C. ina microwave oven. After cooling, water and DCM were added and the phaseswere separated. The aqueous phase was extracted three times with DCM.The combined organic phases were dried over sodium sulfate, filtered andconcentrated in vacuo. The residue was purified by preparative RP HPLC.The fractions containing the product were combined, the ACN was removedin vacuo and the residue was neutralised with a saturated sodiumhydrogencarbonate solution. After extraction with DCM (three times) theorganic phases were combined, dried over sodium sulfate, filtered andconcentrated in vacuo to yield 60 mg of the title compound. A part ofthis product was dissolved in a mixture of water, ACN and TFA andlyophilised to yield 10 mg of the title compound in the form of its saltwith trifluoroacetic acid.

LC/MS (Method LC4): RT=1.40 min; m/z=321.1 [M+H]⁺

Example 32.[4-(6-Chloro-1-methyl-9H-pyrido[3,4-b]indol-8-yl)-phenyl]-pyridin-2-yl-methanol

Under an argon atmosphere4-(6-chloro-9-ethyl-1-methyl-9H-pyrido[3,4-b]indol-8-yl)benzaldehyde (60mg) was dissolved in dry THF (10 ml) with stirring. The solution wascooled to 0° C. and 2-pyridylmagnesium bromide (2.24 ml; 0.25 M in THF)was added with stirring. After the addition was complete, the ice bathwas removed. After 1 h, further 2-pyridylmagnesium bromide (1.12 ml) wasadded. After 1.5 h a saturated ammonium chloride solution was added, andthe aqueous phase was extracted three times with EA. The combinedorganic phases were dried over sodium sulfate, filtered and concentratedin vacuo. The residue was purified by chromatography over silica gelwith HEP/EA (gradient). The fractions containing the product werecombined and concentrated in vacuo. The product was purified bypreparative RP HPLC. The fractions containing the product were combined,the ACN removed in vacuo, and the residue was lyophilized to yield 60 mgof the title compound in the form of its salt with trifluoroacetic acid.

LC/MS (Method LC4): RT=1.30 min; m/z=400.2 [M+H]⁺

Example 33.8-(4-Methoxy-phenyl)-1-methyl-9H-pyrido[3,4-b]indole-6-carbonitrile

In a microwave vessel6-bromo-8-(4-methoxyphenyl)-1-methyl-9H-pyrido[3,4-b]indole (100 mg,272.30 μmol) was dissolved in NMP (5 ml) and copper(I) cyanide (487.77mg, 5.45 mmol) was added. The mixture was treated for 2 h at 200° C. ina microwave oven. After cooling, a saturated ammonium chloride solutionwas added and the aqueous phase was extracted three times with EA. Thecombined organic phases were dried with sodium sulfate, filtered andconcentrated in vacuo. The residue was purified by preparative RP HPLC.The fractions containing the product were combined, the ACN was removedin vacuo and the residue was lyophilised to yield 30 mg of the titlecompound in the form of its salt with trifluoroacetic acid.

LC/MS (Method LC4): RT=1.32 min; m/z=314.2 [M+H]⁺

Example 34.6-Chloro-1-methyl-8-[4-(quinolin-2-ylmethoxy)-phenyl]-9H-pyrido[3,4-b]indole

a) 4-(6-Chloro-1-methyl-9H-pyrido[3,4-b]indol-8-yl)phenol

A microwave reaction vessel was charged with6-chloro-8-iodo-1-methyl-9H-pyrido[3,4-b]indole (200 mg),4-hydroxyphenylboronic acid (201 mg), BDFP (96 mg), sodium carbonate(248 mg), DME (8 ml) and water (3 ml). After 15 min at 100° C. in amicrowave oven the mixture was cooled, filtered and concentrated invacuo. EA was added to the residue, and the organic phase was washedtwice with water, dried over sodium sulfate, filtered and concentratedin vacuo to yield 167 mg of the title compound, which was directly usedin the next step.

b)6-Chloro-1-methyl-8-[4-(quinolin-2-ylmethoxy)-phenyl]-9H-pyrido[3,4-b]indole

4-(6-Chloro-1-methyl-9H-pyrido[3,4-b]indol-8-yl)phenol (167 mg) wasdissolved in DMF (5 ml). After addition of 2-(chloromethyl)quinolinehydrochloride (125 mg) the reaction mixture war stirred for 3 h at 60°C. Then water was added and the aqueous phase was extracted three timeswith EA. The combined organic phases were washed with brine, dried oversodium sulfate, filtered and concentrated in vacuo. The residue waspurified by preparative RP HPLC. The fractions containing the productwere combined, the ACN was removed in vacuo, and the precipitate formedwas filtered off with suction and dried at 40° C. to yield 50 mg of thetitle compound in the form of its salt with trifluoroacetic acid. 36 mgof this salt was treated with a saturated sodium hydrogencarbonatesolution, the solid was filtered off with suction, washed with water anddried at 40° C. to yield 20 mg of the title compound.

LC/MS (Method LC4): RT=1.62 min; m/z=450.3 [M+H]⁺

Examples 35 and 36.8-(4-Methoxy-phenyl)-1-methyl-9H-pyrido[3,4-b]indole-6-carboxylic acidand 8-(4-Methoxy-phenyl)-1-methyl-9H-pyrido[3,4-b]indole-6-carboxamide

8-(4-Methoxy-phenyl)-1-methyl-9H-pyrido[3,4-b]indole-6-carbonitriletrifluoroacetic acid salt (21 mg) was suspended in concentrated sulfuricacid (3 ml) under cooling in an ice bath, and heated for 4 h at 90° C.After cooling, the mixture was concentrated in vacuo. The residue waspurified by preparative RP HPLC. The fractions containing each of thetwo products were combined, the ACN was removed in vacuo, and theresidue was lyophilised.

Example 35.8-(4-Methoxy-phenyl)-1-methyl-9H-pyrido[3,4-b]indole-6-carboxylic acid

4 mg of the title compound were obtained in the form of its salt withtrifluoroacetic acid.

LC/MS (Method LC4): RT=1.15 min; m/z=333.2 [M+H]⁺

Example 36.8-(4-Methoxy-phenyl)-1-methyl-9H-pyrido[3,4-b]indole-6-carboxamide

7 mg of the title compound were obtained in the form of its salt withtrifluoroacetic acid.

LC/MS (Method LC8): RT=2.33 min; m/z=332.2 [M+H]⁺

Example 37.8-[3-(5-Bromo-pyrimidin-2-yloxy)-phenyl]-6-chloro-1-methyl-9H-pyrido[3,4-b]indole

a) 3-(6-Chloro-1-methyl-9H-pyrido[3,4-b]indol-8-yl)phenol

Three microwave reaction vessels were each charged with6-chloro-8-iodo-1-methyl-9H-pyrido[3,4-b]indole (200 mg),3-hydroxyphenylboronic acid (200 mg), sodium carbonate (247 mg), BDFP(96 mg), DME (8 ml) and water (3 ml). After 15 min at 100° C. in amicrowave oven the mixtures of the three vessels were combined, filteredand concentrated in vacuo. EA was added to the residue and the organicphase was washed twice with water, dried over sodium sulfate, filteredand concentrated in vacuo. The residue was treated with diethyl etherand filtered off with suction to yield 541 mg of the title compound,which was directly used in the next step.

b)8-[3-(5-Bromo-pyrimidin-2-yloxy)-phenyl]-6-chloro-1-methyl-9H-pyrido[3,4-b]indole

4-(6-Chloro-1-methyl-9H-pyrido[3,4-b]indol-8-yl)phenol (135 mg) wasdissolved in DMF (5 ml). After addition of 5-bromo-2-chloropyrimidine(101 mg), the reaction mixture war stirred for 3 h at 60° C. Then waterwas added and the aqueous phase was extracted three times with DCM. Thecombined organic phases were washed with brine, dried over sodiumsulfate, filtered and concentrated in vacuo. The residue was purified bypreparative RP HPLC. The fraction containing the product were combined,the ACN was removed in vacuo and the residue was lyophilized. Theproduct was further purified by chromatography over silica gel withEA/HEP (1:1 to 1:0). The fractions containing the product were combinedand concentrated in vacuo. The residue was lyophilized in water/TFA toyield 48 mg of the title compound in the form of its salt withtrifluoroacetic acid.

LC/MS (Method LC5): RT=1.54 min; m/z=465.1 [M+H]⁺

Example 38.6-Bromo-9-ethyl-1-methyl-8-(1-quinolin-2-ylmethyl-1H-pyrazol-4-yl)-9H-pyrido[3,4-b]indole

In a microwave reaction vessel (10 ml) dry DMF (5 ml) was added to6-bromo-9-ethyl-1-methyl-8-(1H-pyrazol-4-yl)-9H-pyrido[3,4-b]indole (50mg, 140.75 μmol) and 2-(chloromethyl)quinoline hydrochloride (45.20 mg,211.13 μmol), followed by cesium carbonate (138 mg) The mixture wastreated for 2 h at 120° C. in a microwave oven. Then further cesiumcarbonate (69 mg) was added and the mixture treated for another 2 h at120° C. in a microwave oven. After filtration, the mixture wasconcentrated in vacuo, and the residue was purified by preparative RPHPLC. The fractions containing the product were combined, the ACN wasremoved in vacuo and the residue lyophilised to yield 42 mg of the titlecompound in the form of its salt with trifluoroacetic acid.

LC/MS (Method LC4): RT=1.50 min; m/z=496.3 [M+H]⁺

Example 39.6-Chloro-1-methyl-8-[4-(1-methyl-1H-imidazol-2-ylmethoxy)-phenyl]-9H-pyrido[3,4-b]indole

Dry DMF (4 ml) was added to4-(6-chloro-1-methyl-9H-pyrido[3,4-b]indol-8-yl)phenol (90 mg),2-(chloromethyl)-1-methyl-1H-imidazole hydrochloride (49 mg) andpotassium carbonate (201 mg), and the mixture was stirred for 2 h at 60°C. Then water was added, and the precipitate was filtered off withsuction and purified by chromatography over silica gel with EA/HEP (2:3to 1:0), followed by DCM. The fractions containing the product werecombined and concentrated in vacuo. The residue was dissolved in 1 Nhydrochloric acid and the solution washed with DCM. Then a 1 N sodiumhydroxide solution was added and the precipitate was filtered off. Afterwashing with water the precipitate was dried at 40° C. to yield 23 mg ofthe title compound.

LC/MS (Method LC5): RT=1.11 min; m/z=403.2 [M+H]⁺

Example 40.6-Chloro-8-[4-([1,4]dioxan-2-ylmethoxy)-phenyl]-1-methyl-9H-pyrido[3,4-b]indole

Dry DMF (4 ml) was added to4-(6-chloro-1-methyl-9H-pyrido[3,4-b]indol-8-yl)phenol (100 mg),1,4-dioxan-2-ylmethyl 4-methylbenzenesulfonate (97 mg) and cesiumcarbonate (530 mg), and the mixture was stirred for 4 h at 80° C. Then asaturated sodium hydrogencarbonate solution was added, and the aqueousphase was extracted three times with DCM. The combined organic phaseswere dried over sodium sulfate, filtered and concentrated in vacuo. Theresidue was purified by preparative RP HPLC. The fractions containingthe product were combined, the ACN was removed in vacuo and the residuewas lyophilized to yield 62 mg of the title compound in the form of itssalt with trifluoroacetic acid. 33 mg of this salt was treated with asaturated sodium hydrogencarbonate solution and DCM. After phaseseparation the aqueous phase was extracted twice with DCM. The combinedorganic phases were dried over sodium sulfate, filtered and concentratedin vacuo to yield 12 mg of the title compound.

LC/MS (Method LC5): RT=1.45 min; m/z=409.3 [M+H]⁺

Example 41.6-Chloro-1-methyl-8-[4-(quinazolin-2-ylmethoxy)-phenyl]-9H-pyrido[3,4-b]indole

Dry DMF (4 ml) was added to4-(6-chloro-1-methyl-9H-pyrido[3,4-b]indol-8-yl)phenol (100 mg),2-(chloromethyl)quinazoline (61 mg) and potassium carbonate (224 mg),and the mixture was stirred for 4 h at 80° C. Then further potassiumcarbonate (10 mg) was added and the mixture stirred for another 3 h at80° C. After cooling, a saturated sodium hydrogencarbonate solution wasadded and the aqueous phase was extracted three times with DCM. Thecombined organic phases were dried over sodium sulfate, filtered andconcentrated in vacuo. The residue was purified by preparative RP HPLC.The fractions containing the product were combined, the ACN was removedin vacuo and the residue was lyophilized to yield 37 mg of the titlecompound in the form of its salt with trifluoroacetic acid. 29 mg ofthis salt was treated with a saturated sodium hydrogencarbonate solutionand the mixture stirred for 2 h. Then the solid was filtered off, washedwith water and dried at 40° C. to yield 18 mg of the title compound.

LC/MS (Method LC5): RT=1.51 min; m/z=451.2 [M+H]+Examples 42 and 43.8-(4-[2-(4-Bromo-1H-pyrazol-1-yl)-ethoxy]-phenyl)-6-chloro-1-methyl-9H-pyrido[3,4-b]indoleand3-bromo-8-(4-[2-(4-bromo-1H-pyrazol-1-yl)-ethoxy]-phenyl)-6-chloro-1-methyl-9H-pyrido[3,4-b]indole

Dry DMF (4 ml) was added to8-(4-(2-(1H-pyrazol-1-yl)ethoxy)phenyl)-6-chloro-1-methyl-9H-pyrido[3,4-b]indole(52 mg), followed by N-bromosuccinimide (44 mg) The mixture was stirredfor 3 h at 40° C. Further N-bromosuccinimide (22 mg) was added and themixture stirred for another 3 h at 40° C. After standing overnight atroom temperature, water was added and the aqueous phase was extractedthree times with DCM. The combined organic phases were dried over sodiumsulfate, filtered and concentrated in vacuo. The residue was purified bypreparative RP HPLC. The fraction containing each of the two productswere combined, the ACN was removed in vacuo and the residue waslyophilized.

Example 42.8-(4-[2-(4-Bromo-pyrazol-1-yl)-ethoxy]-phenyl)-6-chloro-1-methyl-9H-pyrido[3,4-b]indole

7 mg of the title compound were obtained in the form of its salt withtrifluoroacetic acid.

LC/MS (Method LC5): RT=1.57 min; m/z=481.1 [M+H]⁺

Example 43.3-Bromo-8-(4-[2-(4-bromo-pyrazol-1-yl)-ethoxy]-phenyl)-6-chloro-1-methyl-9H-pyrido[3,4-b]indole

5 mg of the title compound were obtained in the form of its salt withtrifluoroacetic acid.

LC/MS (Method LC5): RT=2.13 min; m/z=559.0 [M+H]⁺

Example 44.2-[4-(6-Chloro-9-ethyl-1-methyl-9H-pyrido[3,4-b]indol-8-yl)-pyrazol-1-yl]-ethanol

8-(1-((1,3-Dioxolan-2-yl)methyl)-1H-pyrazol-4-yl)-6-chloro-9-ethyl-1-methyl-9H-pyrido[3,4-b]indoletrifluoroacetic acid salt (55 mg) was stirred in a mixture of ACN (1.5ml) and 2 N hydrochloric acid (0.5 ml) for 16 h. After removal of thesolvent in vacuo the residue was purified by preparative RP HPLC. Thefractions containing the product were combined, the ACN was removed invacuo and the residue was lyophilized to yield 18 mg of the titlecompound in the form of its salt with trifluoroacetic acid.

LC/MS (Method LC4): RT=1.16 min; m/z=355.2 [M+H]⁺

Example 45.6-Chloro-1,5-dimethyl-8-[4-(2-pyrazol-1-yl-ethoxy)-phenyl]-9H-pyrido[3,4-b]pyridine

The title compound was synthesized analogously to the synthesis of thecompound of example 8, using 185 mg of6-chloro-8-iodo-1,5-dimethyl-9H-pyrido[3,4-b]indole and 170 mg of1-(2-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenoxy)ethyl)-1H-pyrazoleand treating the reaction mixture in a microwave oven for 15 min at 100°C. After purification by HPLC, the residue of the extraction with EA wasdirectly lyophilized, using water/ACN as the solvent. 129 mg of thetitle compound was obtained.

LC/MS (Method LC5): RT=1.52 min; m/z=417.1 [M+H]⁺

Example 46.6-Chloro-9-cyclopropylmethyl-8-(2,6-dichloro-pyridin-3-yl)-pyrido[3,4-b]indole

8-Bromo-6-chloro-9-cyclopropylmethyl-pyrido[3,4-b]indole (3 g, 8.94mmol) was dissolved in degassed DME (150 ml) and degassed water (48 ml).After addition of sodium carbonate (3.8 g, 35.75 mmol) the reactionmixture was flushed with argon. After heating to reflux,2,6-dichloro-3-pyridinylboronic acid (3.4 g, 17.72 mmol) and BDFP (1.46g, 1.79 mmol) were dissolved in dry DMF (45 ml), and the solution addedto the reaction mixture via a syringe pump over 8 h. After 2.5 h anextra amount of 1.46 g (1.79 mmol) of BDFP was added to the reactionmixture. When the addition via the syringe pump was finished, themixture was cooled, filtered, the precipitate washed with DCM and thefiltrate concentrated in vacuo. The crude product was purified bypreparative HPLC. The fractions containing the product were combined andlyophilized. 1.33 g of the title compound were obtained in the form of6-chloro-9-cyclopropylmethyl-8-(2,6-dichloro-pyridin-3-yl)-pyrido[3,4-b]indoletrifluoroacetic acid salt. This salt was dissolved in EA, and thesolution washed with a saturated sodium hydrogencarbonate solution andwater. The organic phase was dried over sodium sulfate, filtered andconcentrated in vacuo. The residue was purified by chromatography over a30 g SiO₂ cartridge (EA:HEP 4:1). The fractions containing the productwere concentrated in vacuo and the residue was treated with a HEP/EAmixture (15 ml, 4:1) and the mixture treated in a sonication bath. Thesolvent was removed in vacuo and the obtained solid dried under highvacuum to yield 711 mg of the title compound.

LC/MS (Method LC3): RT=1.08 min; m/z=402.0 [M+H]⁺

Example 47.5-(6-Chloro-9-cyclopropylmethyl-1-methyl-9H-pyrido[3,4-b]indol-8-yl)-pyridine-2-carbonitrile

Degassed dioxane (15 ml, abs.) and degassed water (4 ml) were charged ina 25 ml two-necked flask under argon.8-Bromo-6-chloro-9-cyclopropylmethyl-1-methyl-pyrido[3,4-b]indole (300mg, 0.86 mmol), sodium carbonate (272.8 mg, 2.57 mmol),2-cyanopyridine-5-boronic acid pinacol ester (217.0 mg, 0.94 mmol) andBDFP (175.2 mg, 0.21 mmol) were added, and the mixture was heated underreflux for 12 h. EA (5 ml) was added, the reaction mixture was filteredthrough a kieselgur cartridge and eluted with EA (4×10 ml). The combinedorganic phases were concentrated and the residue was purified bypreparative HPLC. 149 mg (36%) of the title compound was obtained in theform of its salt with trifluoroacetic acid. LC/MS (Method LC6): RT=1.10min; m/z=373.2 [M+H]⁺

Example 48.5-(6-Chloro-9-cyclopropylmethyl-1-methyl-9H-pyrido[3,4-b]indol-8-yl)-3-methyl-pyridine-2-carbonitrile

8-Bromo-6-chloro-9-cyclopropylmethyl-1-methyl-pyrido[3,4-b]indole (300.0mg, 0.86 mmol), cesium carbonate (559.0 mg, 1.72 mmol), BDFP (201.0 mg,0.25 mmol) and 2-cyano-3-methylpyridine-5-boronic acid pinacol ester(419 mg, 1.72 mmol) were reacted and worked up analogously as describedfor the compound of example 47. 273 mg (64%) of the title compound wasobtained in the form of its salt with trifluoroacetic acid.

LC/MS (Method LC6): RT=1.13 min; m/z=387.1 [M+H]⁺

Example 49.6-Chloro-9-cyclopropymethyl-1-methyl-8-(4-methyl-3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazin-7-yl)-9H-pyrido[3,4-b]indole

8-Bromo-6-chloro-9-cyclopropylmethyl-1-methyl-pyrido[3,4-b]indole (250.0mg, 0.71 mmol), sodium carbonate (227.3 mg, 2.15 mmol), BDFP (146.0 mg,0.18 mmol) and4-methyl-7-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazine(197 mg, 0.72 mmol) were reacted and worked up analogously as describedfor the compound of example 47. 335 mg (88%) of the title compound wasobtained in the form of its salt with trifluoroacetic acid.

LC/MS (Method LC6): RT=1.09 min; m/z=419.2 [M+H]⁺

Example 50.6-Chloro-9-cyclopropylmethyl-1-methyl-8-(6-pyrrolidin-1-ylpyridin-3-yl)-9H-pyrido[3,4-b]indole

8-Bromo-6-chloro-9-cyclopropylmethyl-1-methyl-pyrido[34-b]indole (270mg, 0.77 mmol), cesium carbonate (403 mg, 1.54 mmol),2-(pyrrolidin-1-yl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine(424 mg, 1.55 mmol) and BDFP (45 mg) were reacted and worked upanalogously as described for the compound of example 47. 213 mg (52%) ofthe title compound was obtained in the form of its salt withtrifluoroacetic acid.

LC/MS (Method LC6): RT=1.01 min; m/z=417.2 [M+H]⁺

Example 51.6-Chloro-9-cyclopropylmethyl-1-methyl-8-[6-(4-methyl-piperazin-1-yl)-pyridin-3-yl]-pyrido[3,4-b]indole

8-Bromo-6-chloro-9-cyclopropylmethyl-1-methyl-pyrido[3,4-b]indole (270mg, 0.77 mmol), cesium carbonate (504 mg, 1.55 mmol),2-(4-methylpiperazin-1-yl)pyridine-5-boronic acid pinacol ester (469 mg,1.55 mmol) and BDFP (181 mg, 0.22 mmol) were reacted and worked upanalogously as described for the compound of example 47. 320 mg (74%) ofthe title compound was obtained in the form of its salt withtrifluoroacetic acid.

LC/MS (Method LC6): RT=0.93 min; m/z=446.2 [M+H]⁺

Example 52.6-Chloro-8-(4-methoxy-phenyl)-9-(3-methyl-oxetan-3-ylmethyl)-9H-pyrido[3,4-b]indole

A microwave reaction vessel was charged with8-bromo-6-chloro-9-(3-methyl-oxetan-3-ylmethyl)-9H-pyrido[3,4-b]indole(173 mg), sodium carbonate (201 mg),2-(4-methoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (166 mg),BDFP (77 mg), DME (6 ml) and water (2 ml). After 12 min at 130° C. in amicrowave oven the mixture was filtered and the filtrate concentrated invacuo. The residue was first purified by chromatography over silica gelfollowed by a further purification by preparative RP HPLC. The fractionscontaining the product were combined, the ACN was removed in vacuo, theaqueous phase set to a basic pH with saturated sodium hydrogencarbonatesolution, and extracted three times with EA. The combined organic phaseswere dried over sodium sulfate, filtered and concentrated in vacuo toyield 103 mg of the title compound.

LC/MS (Method LC5): RT=1.70 min; m/z=393.3 [M+H]⁺

Example 53.6-Chloro-5-(6-chloro-9-cyclopropylmethyl-9H-pyrido[3,4-b]indol-8-yl)-pyridin-2-ylamine

In a microwave vessel6-chloro-9-cyclopropylmethyl-8-(2,6-dichloro-pyridin-3-yl)-pyrido[3,4-b]indole(20 mg) was dissolved in N-methyl-2-pyrrolidinone (0.5 ml), and anammonia solution (0.1 ml, 25% in water) was added. After 2 h at 160° C.in a microwave oven further ammonia solution (0.1 ml) was added andheating was continued for 1.75 h at 200° C. After cooling, the mixturewas concentrated in vacuo and the residue purified by preparative RPHPLC. The fractions containing the product were combined, the ACN wasremoved in vacuo and the residue was lyophilized to yield 30 mg of thetitle compound in the form of its salt with trifluoroacetic acid.

LC/MS (Method LC5): RT=1.59 min; m/z=383.1 [M+H]⁺

The example compounds of the formula I listed in Table 1 weresynthesized analogously to the syntheses of example compounds of theformula I described above. In Table 1, in the column “Ex. No.” thenumber of the example is given, in the column “LC/MS” the number of theHPLC method specified above which was used in the LC/MS characterizationof the example compound is given, in the column “RT” the observed HPLCretention time in minutes is given, and in the column “MS” themass-to-charge ratio m/z of the observed molecular ion or a related ionand the kind of the ion is given. Like in the case of the compounds ofthe formula I whose synthesis is described in detail above, theionization method in the MS characterization was ES+ if the specifiedion is [M+H]⁺ or another positive ion, and ES− if the specified ion is[M−H]⁻ or another negative ion.

TABLE 1 Ex. LC/ RT No. Structure Name MS [min] MS 54

6-Chloro-8-(6- chloro-pyridin-3- yl)-9-ethyl-9H- pyrido[3,4- b]indoleLC10 2.77 342.0 [M + H]⁺ 55

6-Chloro-8-(2,6- dichloro-pyridin-3- yl)-9-ethyl-9H- pyrido[3,4-b]indole LC9 2.10 376.1 [M + H]⁺ 56

6-Chloro-8-(2- chloro-pyridin-3- yl)-9-ethyl-9H- pyrido[3,4- b]indoleLC11 2.62 342.1 [M + H]⁺ 57

6-Chloro-8- pyridin-3-yl-9- (2,2,2-trifluoro- ethyl)-9H- pyrido[3,4-b]indole LC1 1.21 362.1 [M + H]⁺ 58

6-Chloro-8-(2- chloro-pyridin-3- yl)-9-ethyl-1- methyl-9H- pyrido[3,4-b]indole LC1 1.36 356.1 [M + H]⁺ 59

6-Chloro-8-(2,6- dichloro-pyridin-3- yl)-9-ethyl-1- methyl-9H-pyrido[3,4- b]indole LC6 1.15 390.1 [M + H]⁺ 60

5-[6-Chloro-9- (2,2,2-trifluoro- ethyl)-9H- pyrido[3,4-b]indol-8-yl]-pyridine-2- carbonitrile LC8 3.86 387.2 [M + H]⁺ 61

6-Chloro-8- quinolin-3-yl-9- (2,2,2-trifluoro- ethyl)-9H- pyrido[3,4-b]indole LC3 1.45 412.2 [M + H]⁺ 62

6-Chloro-8-(6- methoxy-pyridin- 3-yl)-9-(2,2,2- trifluoro-ethyl)-9H-pyrido[3,4- b]indole LC11 2.85 392.1 [M + H]⁺ 63

6-Chloro-8-(2,6- difluoro-pyridin-3- yl)-9-(2,2,2- trifluoro-ethyl)-9H-pyrido[3,4- b]indole LC11 2.84 398.2 [M + H]⁺ 64

6-Chloro-8-(2,6- dichloro-pyridin-3- yl)-1-methyl-9H- pyrido[3,4-b]indole LC6 1.05 362.0 [M + H]⁺ 65

6-Chloro-1- methyl-8-pyridin- 3-yl-9H- pyrido[3,4- b]indole LC11 2.12[M + H]⁺ 294.2 66

6-Chloro-8-(6- chloro-pyridin-3- yl)-9-(2,2,2- trifluoro-ethyl)-9H-pyrido[3,4- b]indole LC8 3.89 396.2 [M + H]⁺ 67

6-Chloro-9-ethyl- 8-(6-methyl- pyridin-3-yl)-9H- pyrido[3,4- b]indoleLC11 2.10 322.2 [M + H]⁺ 68

6-Chloro-8-(6- methyl-pyridin-3- yl)-9-(2,2,2- trifluoro-ethyl)-9H-pyrido[3,4- b]indole LC11 2.22 376.2 [M + H]⁺ 69

6-Chloro-8-(4- chloro-pyridin-3- yl)-9-(2,2,2- trifluoro-ethyl)-9H-pyrido[3,4- b]indole LC1 1.46 396.0 [M + H]⁺ 70

6-Chloro-9-ethyl- 8-(6-methoxy- pyridin-3-yl)-9H- pyrido[3,4- b]indoleLC11 2.77 338.2 [M + H]⁺ 71

6-Chloro-8-(1H- pyrrolo[2,3- b]pyridin-5-yl)-9- (2,2,2-trifluoro-ethyl)-9H- pyrido[3,4- b]indole LC4 1.52 401.2 [M + H]⁺ 72

6-Chloro-8-(6- methoxy-pyridin- 3-yl)-9H- pyrido[3,4- b]indole LC6 1.35310.1 [M + H]⁺ 73

6-Chloro-8-(6- chloro-pyridin-3- yl)-9H-pyrido[3,4- b]indole LC1 1.34314.0 [M + H]⁺ 74

6-Chloro-8-(2,6- dichloro-pyridin-3- yl)-9H-pyrido[3,4- b]indole LC11.43 348.0 [M + H]⁺ 75

6-Chloro-8-(6- methyl-pyridin-3- yl)-9H-pyrido[3,4- b]indole LC1 1.06294.1 [M + H]⁺ 76

6-Chloro-8-(5- chloro-thiophen-3- yl)-9-(2,2,2- trifluoro-ethyl)-9H-pyrido[3,4- b]indole LC6 1.29 401.1 [M + H]⁺ 77

6-Chloro-8-(6- chloro-pyridin-3- yl)-1-methyl-9H- pyrido[3,4- b]indoleLC3 1.03 328.0 [M + H]⁺ 78

6-Chloro-8-(5- chloro-pyridin-3- yl)-9-ethyl-1- methyl-9H- pyrido[3,4-b]indole LC1 1.40 356.1 [M + H]⁺ 79

6-Chloro-8-(6- chloro-pyridin-3- yl)-9-ethyl-1- methyl-9H- pyrido[3,4-b]indole LC3 1.09 356.0 [M + H]⁺ 80

(5-[6-Chloro-9- (2,2,2-trifluoro- ethyl)-9H- pyrido[3,4-b]indol-8-yl]-pyridin-2-yl)- cyclohexyl-amine LC6 1.11 459.3 [M + H]⁺ 81

6-Chloro-8-(6- pyrrolidin-1-yl- pyridin-3-yl)-9- (2,2,2-trifluoro-ethyl)-9H- pyrido[3,4- b]indole LC12 2.68 431.1 [M + H]⁺ 82

6-Chloro-8-(5- fluoro-pyridin-3- yl)-9-(2,2,2- trifluoro-ethyl)-9H-pyrido[3,4- b]indole LC12 3.29 380.0 [M + H]⁺ 83

6-Chloro-8-(6- chloro-2-methyl- pyridin-3-yl)-9- (2,2,2-trifluoro-ethyl)-9H- pyrido[3,4- b]indole LC12 3.62 410.0 [M + H]⁺ 84

(5-[6-Chloro-9- (2,2,2-trifluoro- ethyl)-9H- pyrido[3,4-b]indol-8-yl]-pyridin-2-yl)- dimethyl-amine LC12 2.57 405.1 [M + H]⁺ 85

6-Chloro-8-(5- fluoro-6-methoxy- pyridin-3-yl)-9- (2,2,2-trifluoro-ethyl)-9H- pyrido[3,4- b]indole LC12 3.82 410.2 [M + H]⁺ 86

6-Chloro-8-(6- morpholin-4-yl- pyridin-3-yl)-9- (2,2,2-trifluoro-ethyl)-9H- pyrido[3,4- b]indole LC12 3.55 447.1 [M + H]⁺ 87

6-Chloro-8-[6-(4- methyl-piperazin- 1-yl)-pyridin-3-yl]-9-(2,2,2-trifluoro- ethyl)-9H- pyrido[3,4- b]indole LC12 2.82 460.1 [M +H]⁺ 88

6-Chloro-9-(2,2,2- trifluoro-ethyl)-8- (6-trifluoromethyl-pyridin-3-yl)-9H- pyrido[3,4- b]indole LC12 3.75 430.0 [M + H]⁺ 89

6-Chloro-8- (3,4,5,6- tetrahydro-2H- [1,2′]bipyridinyl-5′- yl)-9-(2,2,2-trifluoro-ethyl)-9H- pyrido[3,4- b]indole LC4 1.72 445.2 [M + H]⁺ 90

9-But-2-ynyl-6- chloro-8-(6- chloro-pyridin-3- yl)-9H-pyrido[3,4-b]indole LC12 3.35 366.1 [M + H]⁺ 91

6-Chloro-9-ethyl- 8-(6-methoxy- pyridin-3-yl)-1- methyl-9H- pyrido[3,4-b]indole LC8 3.25 352.2 [M + H]⁺ 92

6-Chloro-9-ethyl- 1-methyl-8-(1H- pyrrolo[2,3- b]pyridin-5-yl)-9H-pyrido[3,4- b]indole LC6 1.06 361.2 [M + H]⁺ 93

6-Chloro-9-ethyl- 1-methyl-8-(6- morpholin-4-yl- pyridin-3-yl)-9H-pyrido[3,4- b]indole LC6 0.97 407.2 [M + H]⁺ 94

6-Chloro-8-(6- methoxy-pyridin- 3-yl)-1-methyl-9H- pyrido[3,4- b]indoleLC6 1.07 324.2 [M + H]⁺ 95

6-Chloro-1- methyl-8-(6- methyl-pyridin-3- yl)-9H-pyrido[3,4- b]indoleLC6 1.07 308.2 [M + H]⁺ 96

6-Chloro-1- methyl-8-(6- morpholin-4-yl- pyridin-3-yl)-9H- pyrido[3,4-b]indole LC6 1.02 377.3 [M − H]⁻ 97

6-Chloro-8-(4- chloro-pyridin-3- yl)-1-methyl-9H- pyrido[3,4- b]indoleLC4 1.52 328.0 [M + H]⁺ 98

6-Bromo-8-(2,6- dichloro-pyridin-3- yl)-1-methyl-9H- pyrido[3,4-b]indole LC8 3.21 406.1 [M + H]⁺ 99

6-Chloro-8-(5- fluoro-6-methoxy- pyridin-3-yl)-1- methyl-9H- pyrido[3,4-b]indole LC6 1.09 342.1 [M + H]⁺ 100

5-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-pyridine-2-carbonitrile LC6 1.01 319.1 [M + H]⁺ 101

6-Chloro-1- methyl-8-(3,4,5,6- tetrahydro-2H- [1,2′]bipyridinyl-5′-yl)-9H-pyrido[3,4- b]indole LC6 1.32 377.3 [M + H]⁺ 102

6-Chloro-8-(6- isopropoxy- pyridin-3-yl)-1- methyl-9H- pyrido[3,4-b]indole LC3 1.02 352.1 [M + H]⁺ 103

6-Chloro-8-(2- chloro-6-methoxy- pyridin-3-yl)-1- methyl-9H- pyrido[3,4-b]indole LC3 0.99 358.1 [M + H]⁺ 104

6-Chloro-8-(6- methoxy-2- methyl-pyridin-3- yl)-1-methyl-9H- pyrido[3,4-b]indole LC3 0.98 338.1 [M + H]⁺ 105

6-Chloro-8-(2,6- dichloro-pyridin-3- yl)-1-ethyl-9H- pyrido[3,4-b]indole LC8 3.54 376.1 [M + H]⁺ 106

6-Chloro-8-(2,6- dichloro-pyridin-3- yl)-1-isopropyl- 9H-pyrido[3,4-b]indole LC3 1.04 390.1 [M + H]⁺ 107

5′-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-[1,2′]bipyridinyl-2- one LC3 1.00 387.0 [M + H]⁺ 108

8-(2,6-Dichloro- pyridin-3-yl)-1,6- dimethyl-9H- pyrido[3,4- b]indoleLC8 3.27 342.1 [M + H]⁺ 109

4-[5-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-pyridin-2-yl]-piperazin-2-one LC3 0.94 392.0 [M + H]⁺ 110

3-[5-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-pyridin-2-yl]-oxazolidin-2-one LC3 1.02 379.0 [M + H]⁺ 111

6-Chloro-8-(2,6- dichloro-pyridin-3- yl)-9-(2-methoxy- ethyl)-9H-pyrido[3,4- b]indole LC3 1.14 406.0 [M + H]⁺ 112

6-Chloro-8-(1- pyridin-4- ylmethyl-1H- pyrazol-4-yl)-9-(2,2,2-trifluoro- ethyl)-9H- pyrido[3,4- b]indole LC3 1.01 442.0 [M +H]⁺ 113

3-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-6-methoxy-pyridin-2-ylamine LC8 3.03 339.1 [M + H]⁺ 114

6-Chloro-8-(2- chloro-3-methyl- 3H-imidazol-4-yl)- 9-(2,2,2-trifluoro-ethyl)-9H- pyrido[3,4- b]indole LC3 1.12 399.1 [M + H]⁺ 115

6-Chloro-1- methyl-8-(1- pyridin-3- ylmethyl-1H- pyrazol-4-yl)-9H-pyrido[3,4- b]indole LC4 1.17 374.3 [M + H]⁺ 116

6-Chloro-9-ethyl- 1-methyl-8-(1- pyridin-3- ylmethyl-1H-pyrazol-4-yl)-9H- pyrido[3,4- b]indole LC4 1.22 402.3 [M + H]⁺ 117

6-Chloro-8-(2,6- dichloro-pyridin-3- yl)-1-methyl-9H- pyrido[3,4-b]indole-3- carboxylic acid methyl ester LC4 2.06 420.1 [M + H]⁺ 118

6-Chloro-1- methyl-8-[6-(4- methyl-piperazin- 1-yl)-pyridin-3-yl]-9H-pyrido[3,4- b]indole LC4 1.24 390.4 [M − H]⁻ 119

8-(2-Benzyloxy- pyridin-3-yl)-6- chloro-1-methyl- 9H-pyrido[3,4-b]indole LC4 1.73 400.1 [M + H]⁺ 120

6-Chloro-1- methyl-8-(6- methylsulfanyl- pyridin-3-yl)-9H- pyrido[3,4-b]indole LC4 1.45 340.1 [M + H]⁺ 121

6-Chloro-8-[1- (2,6-dimethyl- pyridin-3- ylmethyl)-1H- pyrazol-4-yl]-9-ethyl-1-methyl- 9H-pyrido[3,4- b]indole LC4 1.08 430.3 [M + H]⁺ 122

6-Chloro-8-(6- chloro-2-methoxy- pyridin-3-yl)-1- methyl-9H- pyrido[3,4-b]indole LC4 1.52 358.2 [M + H]⁺ 123

6-Chloro-9-ethyl- 8-pyridin-4-yl-9H- pyrido[3,4- b]indole LC9 1.49 308.2[M + H]⁺ 124

6-Chloro-9-ethyl- 8-furan-2-yl-9H- pyrido[3,4- b]indole LC2 1.35 297.1[M + H]⁺ 125

6-Chloro-9-ethyl- 1-methyl-8- pyridin-4-yl-9H- pyrido[3,4- b]indole LC30.95 322.1 [M + H]⁺ 126

6-Chloro-8- pyrimidin-5-yl-9- (2,2,2-trifluoro- ethyl)-9H- pyrido[3,4-b]indole LC1 1.30 363.1 [M + H]⁺ 127

6-Chloro-8- pyridin-4-yl-9- (2,2,2-trifluoro- ethyl)-9H- pyrido[3,4-b]indole LC1 1.20 362.1 [M + H]⁺ 128

6-Chloro-8- phenyl-9-(2,2,2- trifluoro-ethyl)-9H- pyrido[3,4- b]indoleL08 4.54 361.0 [M + H]⁺ 129

6-Chloro-8-(4- chloro-phenyl)-9- (2,2,2-trifluoro- ethyl)-9H-pyrido[3,4- b]indole LC3 1.35 394.9 [M + H]⁺ 130

6-Chloro-1- methyl-8-pyridin- 4-yl-9H- pyrido[3,4- b]indole LC3 0.86294.0 [M + H]⁺ 131

6-Chloro-8-(4- chloro-phenyl)-9- ethyl-9H- pyrido[3,4- b]indole LC113.10 341.2 [M + H]⁺ 132

5-[6-Chloro-9- (2,2,2-trifluoro- ethyl)-9H- pyrido[3,4-b]indol-8-yl]-pyrimidin-2- ylamine LC11 2.39 378.2 [M + H]⁺ 133

6-Chloro-9-ethyl- 8-pyrimidin-5-yl- 9H-pyrido[3,4- b]indole LC1 1.20309.1 [M + H]⁺ 134

6-Chloro-8-(5- chloro-thiophen-2- yl)-9-(2,2,2- trifluoro-ethyl)-9H-pyrido[3,4- b]indole LC12 4.22 401.0 [M + H]⁺ 135

6-Chloro-8-(1- methyl-1H- pyrazol-4-yl)-9- (2,2,2-trifluoro- ethyl)-9H-pyrido[3,4- b]indole LC12 3.17 365.1 [M + H]⁺ 136

6-Chloro-8-(3- phenyl-isoxazol-5- yl)-9-(2,2,2- trifluoro-ethyl)-9H-pyrido[3,4- b]indole LC8 4.60 428.2 [M + H]⁺ 137

6-Chloro-8-(1- isobutyl-1H- pyrazol-4-yl)-9- (2,2,2-trifluoro-ethyl)-9H- pyrido[3,4- b]indole LC12 3.79 407.1 [M + H]⁺ 138

6-Chloro-9-(2,2,2- trifluoro-ethyl)-8- (1,3,5-trimethyl-1H-pyrazol-4-yl)- 9H-pyrido[3,4- b]indole LC12 3.40 393.1 [M + H]⁺ 139

6-Chloro-8- pyrazolo[1,5- a]pyridin-3-yl-9- (2,2,2-trifluoro- ethyl)-9H-pyrido[3,4- b]indole LC12 3.47 401.1 [M + H]⁺ 140

6-Chloro-8-(2,5- dimethyl-2H- pyrazol-3-yl)-9- (2,2,2-trifluoro-ethyl)-9H- pyrido[3,4- b]indole LC3 1.16 379.0 [M + H]⁺ 141

6-Chloro-8- pyrimidin-5-yl-9H- pyrido[3,4- b]indole LC6 0.88 281.1 [M +H]⁺ 142

6-Chloro-9-ethyl- 8-(4-methoxy- phenyl)-9H- pyrido[3,4- b]indole LC61.14 337.20 [M + H]⁺ 143

6-Chloro-9-ethyl- 8-p-tolyl-9H- pyrido[3,4- b]indole LC6 1.22 321.1 [M +H]⁺ 144

6-Chloro-8-(1H- pyrazol-4-yl)-9- (2,2,2-trifluoro- ethyl)-9H-pyrido[3,4- b]indole LC12 3.09 351.1 [M + H]⁺ 145

6-Chloro-8-(2- chloro-phenyl)-9- ethyl-9H- pyrido[3,4- b]indole LC8 3.96341.1 [M + H]⁺ 146

6-Chloro-9-ethyl- 8-(3-methoxy- phenyl)-9H- pyrido[3,4- b]indole LC83.91 337.1 [M + H]⁺ 147

6-Chloro-9-ethyl- 8-(4-methoxy- phenyl)-1-methyl- 9H-pyrido[3,4-b]indole LC8 3.70 351.2 [M + H]⁺ 148

6-Chloro-8-(4- chloro-phenyl)-9- ethyl-1-methyl- 9H-pyrido[3,4- b]indoleLC4 1.64 355.1 [M + H]⁺ 149

6-Chloro-8-(4- methoxy-phenyl)- 1-methyl-9H- pyrido[3,4- b]indole LC31.10 323.1 [M + H]⁺ 150

6-Chloro-1- methyl-8-p-tolyl- 9H-pyrido[3,4- b]indole LC6 1.15 305.3 [M− H]⁻ 151

6-Chloro-1- methyl-8-(1- methyl-1H- pyrazol-4-yl)-9H- pyrido[3,4-b]indole LC8 2.80 297.2 [M + H]⁺ 152

6-Chloro-8-(4- methoxy-phenyl)- 1-methyl-9H- pyrido[3,4- b]indole-3-carboxylic acid methyl ester LC6 1.36 381.1 [M + H]⁺ 153

6-Chloro-1-ethyl- 8-(4-methoxy- phenyl)-9H- pyrido[3,4- b]indole LC31.01 337.1 [M + H]⁺ 154

5-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-pyrimidin-2- ylamineLC3 0.80 310.1 [M + H]⁺ 155

6-Chloro-8-(4- methoxy-phenyl)- 1-trifluoromethyl- 9H-pyrido[3,4-b]indole LC3 1.32 377.1 [M + H]⁺ 156

6-Chloro-1- methyl -8-(2- pyrrol-1-yl- pyrimidin-5-yl)- 9H-pyrido[3,4-b]indole LC3 1.01 360.1 [M + H]⁺ 157

[5-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-pyrimidin-2-yl]-methyl-amine LC6 0.99 324.1 [M + H]⁺ 158

2,6-Dichloro-3-(6- chloro-1-methyl- 9H-pyrido[3,4- b]indol-8-yl)-benzonitrile LC8 3.64 386.1 [M + H]⁺ 159

6-Chloro-8-(1- ethyl-1H-pyrazol- 4-yl)-9-(2,2,2- trifluoro-ethyl)-9H-pyrido[3,4- b]indole LC3 1.12 379.0 [M + H]⁺ 160

6-Chloro-8-(1- isopropyl-1H- pyrazol-4-yl)-9- (2,2,2-trifluoro-ethyl)-9H- pyrido[3,4- b]indole LC3 1.18 393.0 [M + H]⁺ 161

6-Chloro-8-(1- propyl-1H- pyrazol-4-yl)-9- (2,2,2-trifluoro- ethyl)-9H-pyrido[3,4- b]indole LC3 1.16 393.0 [M + H]⁺ 162

8-(1-Benzyl-1H- pyrazol-4-yl)-6- chloro-9-(2,2,2- trifluoro-ethyl)-9H-pyrido[3,4- b]indole LC8 3.91 441.2 [M + H]⁺ 163

Acetic acid 2-(4- [6-chloro-9-(2,2,2- trifluoro-ethyl)-9H-pyrido[3,4-b]indol- 8-yl]-pyrazol-1-yl)- ethyl ester LC3 1.12 437.0 [M +H]⁺ 164

6-Chloro-9-ethyl- 1-methyl-8-(1- methyl-1H- pyrazol-4-yl)-9H-pyrido[3,4- b]indole LC8 2.87 325.1 [M + H]⁺ 165

6-Chloro-8-(1- methyl-1H-pyrrol- 3-yl)-9-(2,2,2- trifluoro-ethyl)-9H-pyrido[3,4- b]indole LC3 1.25 364.0 [M + H]⁺ 166

6-Chloro-8-(1- thiophen-2- ylmethyl-1H- pyrazol-4-yl)-9-(2,2,2-trifluoro- ethyl)-9H- pyrido[3,4- b]indole LC3 1.21 491.1 [M −H + FA]⁻ 167

6-Chloro-8-[1- (2,6-dichloro- phenyl)-1H- pyrazol-4-yl]-9-(2,2,2-trifluoro- ethyl)-9H- pyrido[3,4- b]indole LC3 1.28 495.1 [M +H]⁺ 168

6-Chloro-8-(1- pyridin-2- ylmethyl-1H- pyrazol-4-yl)-9-(2,2,2-trifluoro- ethyl)-9H- pyrido[3,4- b]indole LC3 1.10 442.1 [M +H]⁺ 169

6-Chloro-8-[1-(2- methoxy-ethyl)- 1H-pyrazol-4-yl]- 9-(2,2,2-trifluoro-ethyl)-9H- pyrido[3,4- b]indole LC3 1.09 409.2 [M + H]⁺ 170

6-Chloro-8-(2- phenyl-thiazol-5- yl)-9-(2,2,2- trifluoro-ethyl)-9H-pyrido[3,4- b]indole LC3 1.37 444.1 [M + H]⁺ 171

6-Chloro-8-(2- methyl-thiazol-5- yl)-9-(2,2,2- trifluoro-ethyl)-9H-pyrido[3,4- b]indole LC3 1.17 382.1 [M + H]⁺ 172

6-Chloro-8-(3,4- dimethoxy- phenyl)-1-methyl- 9H-pyrido[3,4- b]indoleLC3 0.95 353.3 [M + H]⁺ 173

6-Chloro-8-(1- cyclopropylmethyl- 1H-pyrazol-4-yl)- 9-(2,2,2-trifluoro-ethyl)-9H- pyrido[3,4- b]indole LC3 1.18 405.2 [M + H]⁺ 174

6-Chloro-8-(2- cyclopropyl- thiazol-5-yl)-9- (2,2,2-trifluoro-ethyl)-9H- pyrido[3,4- b]indole LC3 1.26 408.2 [M + H]⁺ 175

6-Chloro-1- methyl-8-(2,4,6- trimethoxy- phenyl)-9H- pyrido[3,4-b]indole LC3 1.10 383.2 [M + H]⁺ 176

6-Chloro-8-(4- isopropoxy-2- methyl-phenyl)-1- methyl-9H- pyrido[3,4-b]indole LC8 4.05 365.2 [M + H]⁺ 177

8-(4-Benzyloxy- phenyl)-6-chloro- 1-methyl-9H- pyrido[3,4- b]indole LC84.13 399.1 [M + H]⁺ 178

6-Chloro-1- methyl-8-(2,3,4- trimethoxy- phenyl)-9H- pyrido[3,4-b]indole LC4 1.64 381.2 [M − H]⁻ 179

6-Chloro-8-(2,3- dihydro- benzofuran-5-yl)- 1-methyl-9H- pyrido[3,4-b]indole LC4 1.64 335.2 [M + H]⁺ 180

5-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-2-methoxy- phenolLC4 1.54 339.2 [M + H]⁺ 181

6-Chloro-8-(4- cyclopropylmethoxy- phenyl)-1- methyl-9H- pyrido[3,4-b]indole LC4 1.77 363.2 [M + H]⁺ 182

6-Chloro-1- methyl-8-[4-(3- methyl-oxetan-3- ylmethoxy)- phenyl]-9H-pyrido[3,4- b]indole LC4 1.67 393.2 [M + H]⁺ 183

6-Chloro-8-(4- cyclopropoxy- phenyl)-1-methyl- 9H-pyrido[3,4- b]indoleLC4 1.73 349.2 [M + H]⁺ 184

6-Chloro-8- chroman-6-yl-1- methyl-9H- pyrido[3,4- b]indole LC4 1.69349.2 [M + H]⁺ 185

8-(3-Benzyloxy-4- methoxy-phenyl)- 6-chloro-1-methyl- 9H-pyrido[3,4-b]indole LC4 1.65 429.3 [M + H]⁺ 186

5-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-2-methoxy-phenylamine LC4 1.52 338.2 [M + H]⁺ 187

6-Chloro-8-(4- methoxy-2,3- dimethyl-phenyl)- 1-methyl-9H- pyrido[3,4-b]indole LC4 1.75 351.2 [M + H]⁺ 188

6-Bromo-8-(4- methoxy-phenyl)- 1-methyl-9H- pyrido[3,4- b]indole LC31.10 367.1 [M + H]⁺ 189

6-Chloro-8-(4- chloro-phenyl)-1- methyl-9H- pyrido[3,4- b]indole LC41.70 327.2 [M + H]⁺ 190

6-Chloro-8-(2,4- dichloro-phenyl)- 1-methyl-9H- pyrido[3,4- b]indole LC41.61 361.2 [M + H]⁺ 191

6-Chloro-8-(4- methoxy-phenyl)- 9H-pyrido[3,4- b]indole LC4 1.48 309.3[M + H]⁺ 192

6-Chloro-8-(4- ethoxy-phenyl)-1- methyl-9H- pyrido[3,4- b]indole LC41.57 337.31 [M + H]⁺ 193

6-Chloro-8-(2,4- dimethoxy- phenyl)-1-methyl- 9H-pyrido[3,4- b]indoleLC4 1.67 353.3 [M + H]⁺ 194

6-Chloro-8-[4-(2- imidazol-1-yl- ethoxy)-phenyl]-1- methyl-9H-pyrido[3,4- b]indole LC4 1.13 403.3 [M + H]⁺ 195

6-Chloro-8-(2,2- dimethyl-2,3- dihydro- benzofuran-6-yl)- 1-methyl-9H-pyrido[3,4- b]indole LC4 1.76 363.2 [M + H]⁺ 196

6-Chloro-1- methyl-8-(2- methyl-2,3- dihydro- benzofuran-6-yl)-9H-pyrido[3,4- b]indole LC4 1.56 349.2 [M + H]⁺ 197

6-Chloro-1- methyl-8-[4- (tetrahydro-furan- 3-yloxy)-phenyl]-9H-pyrido[3,4- b]indole LC4 1.64 379.3 [M + H]⁺ 198

6-Chloro-1- methyl-8-[3- methyl-4- (tetrahydrofuran- 3-yloxy)-phenyl]-9H-pyrido[3,4- b]indole LC4 1.72 393.3 [M + H]⁺ 199

8-(3-Benzyl-1H- pyrazol-4-yl)-6- chloro-1-methyl- 9H-pyrido[3,4-b]indole LC4 1.57 373.2 [M + H]⁺ 200

6-Chloro-8-(4- methoxy-3- methoxymethyl- phenyl)-1-methyl-9H-pyrido[3,4- b]indole LC8 3.53 367.2 [M + H]⁺ 201

6-Chloro-9-(2- methoxy-ethyl)-8- (4-methoxy- phenyl)-9H- pyrido[3,4-b]indole LC4 1.71 367.2 [M + H]⁺ 202

6-Chloro-1- methyl-8-[4- (pyridin-2- ylmethoxy)- phenyl]-9H- pyrido[3,4-b]indole LC8 3.30 400.2 [M + H]⁺ 203

2-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-1H-indole-5-carboxylic acid ethyl ester LC4 1.71 402.3 [M − H]⁻ 204

2-[4-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-phenyl]-1-(4-pyrrolidin-1-yl- piperidin-1-yl)- ethanone LC8 2.51 487.3 [M + H]⁺ 205

6-Chloro-1- methyl-8-(4- phenoxy-phenyl)- 9H-pyrido[3,4- b]indole (a)LC4 1.68 385.2 [M + H]⁺ 206

6-Chloro-8-(3- chloro-4-methoxy- phenyl)-1-methyl- 9H-pyrido[3,4-b]indole LC4 1.70 357.2 [M + H]⁺ 207

8-(1-Benzyl-1H- pyrazol-4-yl)-6- chloro-9-ethyl-1- methyl-9H-pyrido[3,4- b]indole LC4 1.57 401.2 [M + H]⁺ 208

8-(1-Benzyl-1H- pyrazol-4-yl)-6- bromo-9-ethyl-1- methyl-9H- pyrido[3,4-b]indole LC4 1.58 445.2 [M + H]⁺ 209

6-Bromo-9-ethyl- 1-methyl-8-(1- methyl-1H- pyrazol-4-yl)-9H- pyrido[3,4-b]indole LC4 1.34 369.1 [M + H]⁺ 210

6-Bromo-1,9- diethyl-3-methyl- 8-(1-methyl-1H- pyrazol-4-yl)-9H-pyrido[3,4- b]indole LC4 1.55 397.1 [M + H]⁺ 211

6-Bromo-3-ethyl- 8-(4-methoxy- phenyl)-1-methyl- 9H-pyrido[3,4- b]indoleLC4 1.80 395.1 [M + H]⁺ 212

6-Bromo-3-ethyl- 1-methyl-8-[4-(2- pyrazol-1-yl- ethoxy)-phenyl]-9H-pyrido[3,4- b]indole LC4 1.60 475.2 [M + H]⁺ 213

6-Chloro-1- methyl-8-(2- piperazin-1-yl- pyridin-4-yl)-9H- pyrido[3,4-b]indole LC4 1.03 376.1 [M − H]⁻ 214

6-Chloro-1- methyl-8-[2-(4- methyl-piperazin- 1-yl)-pyridin-4-yl]-9H-pyrido[3,4- b]indole LC4 1.04 390.1 [M − H]⁻ 215

4-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-pyridin-2- ylamineLC4 1.06 309.2 [M + H]⁺ 216

6-Bromo-3,9- diethyl-1-methyl- 8-(1-methyl-1H- pyrazol-4-yl)-9H-pyrido[3,4- b]indole LC4 1.43 397.2 [M + H]⁺ 217

6-Bromo-8-(4- methoxy-phenyl)- 1,3-dimethyl-9H- pyrido[3,4- b]indole LC41.56 381.1 [M + H]⁺ 218

6-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-3-methoxy-pyridin-2-ylamine LC4 1.51 339.2 [M + H]⁺ 219

6-Chloro-9-ethyl- 1-methyl-8-[2-(4- methyl-piperazin-1-yl)-pyridin-4-yl]- 9H-pyrido[3,4- b]indole LC4 1.24 420.2 [M + H]⁺ 220

3-(6-Chloro-9- ethyl-1-methyl- 9H-pyrido[3,4- b]indol-8-yl)- benzamideLC8 2.88 364.1 [M + H]⁺ 221

6-Chloro-8-[3- methoxy-4- (pyridin-2- ylmethoxy)- phenyl]-1-methyl-9H-pyrido[3,4- b]indole LC4 1.62 428.2 [M − H]⁻ 222

8-(4-Benzyloxy-3- methoxy-phenyl)- 6-chloro-1-methyl- 9H-pyrido[3,4-b]indole LC8 3.98 429.2 [M + H]⁺ 223

6-Chloro-8-[4-(6- fluoro-pyridin-2- ylmethoxy)-3- methoxy-phenyl]-1-methyl-9H- pyrido[3,4- b]indole LC4 1.71 446.2 [M − H]⁻ 224

6-Chloro-1- methyl-8-(4- morpholin-4- ylmethyl-phenyl)- 9H-pyrido[3,4-b]indole LC8 2.29 392.1 [M + H]⁺ 225

6-Chloro-8-(4- cyclopentyloxy- phenyl)-1-methyl- 9H-pyrido[3,4- b]indoleLC8 4.18 377.2 [M + H]⁺ 226

6-Chloro-8-[4-(6- fluoro-pyridin-2- ylmethoxy)- phenyl]-1-methyl-9H-pyrido[3,4- b]indole LC4 1.75 418.1 [M + H]⁺ 227

6-Chloro-1- methyl-8-(2- methyl-2H- pyrazol-3-yl)-9H- pyrido[3,4-b]indole LC4 1.44 295.2 [M − H]⁻ 228

6-Chloro-1- methyl-8-[4-(1- methyl-pyrrolidin- 3-ylmethoxy)- phenyl]-9H-pyrido[3,4- b]indole LC4 1.36 406.2 [M + H]⁺ 229

1-[4-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-phenoxy]-3-piperidin-1-yl- propan-2-ol LC4 1.36 450.1 [M + H]⁺ 230

1-[3-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-phenyl]-3-(2,4-difluoro- phenyl)-urea LC4 1.72 463.1 [M + H]⁺ 231

6-Chloro-1- methyl-8-(4- phenethyloxy- phenyl)-9H- pyrido[3,4- b]indoleLC4 1.87 413.1 [M + H]⁺ 232

6-Chloro-8-(1H- indazol-5-yl)-1- methyl-9H- pyrido[3,4- b]indole LC41.53 333.1 [M + H]⁺ 233

6-Chloro-9-ethyl- 1-methyl-8-[1-(2- pyrazol-1-yl- ethyl)-1H-pyrazol-3-yl]-9H- pyrido[3,4- b]indole LC4 1.35 405.2 [M + H]⁺ 234

6-Chloro-9-ethyl- 1-methyl-8-(1H- pyrazol-3-yl)-9H- pyrido[3,4- b]indoleLC8 2.83 311.0 [M + H]⁺ 235

6-Chloro-9-ethyl- 1-methyl-8-[1-(2- pyrazol-1-yl- ethyl)-1H-pyrazol-3-yl]-9H- pyrido[3,4- b]indole LC4 1.49 405.1 [M + H]⁺ 236

6-Chloro-8-(2,2- dimethyl-2,3- dihydro- benzofuran-5-yl)- 1-methyl-9H-pyrido[3,4- b]indole LC4 1.61 363.2 [M + H]⁺ 237

6-Chloro-1- methyl-8-(2- pyrazol-1-yl- pyrimidin-5-yl)- 9H-pyrido[3,4-b]indole LC4 1.31 361.14 [M + H]⁺ 238

[4-(6-Chloro-9- ethyl-1-methyl- 9H-pyrido[3,4- b]indol-8-yl)-phenyl]-phenyl- methanol LC4 1.58 427.2 [M + H]⁺ 239

6-Chloro-9-ethyl- 1-methyl-8-(1H- pyrazol-4-yl)-9H- pyrido[3,4- b]indoleLC4 1.20 311.1 [M + H]⁺ 240

6-(6-Chloro-1,9- dimethyl-9H- pyrido[3,4-b]indol- 8-yl)-3-methoxy-pyridin-2-ylamine LC4 1.17 353.1 [M + H]⁺ 241

4-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-benzylamine LC7 4.51161.6 [M + 2H]⁺⁺ 242

6-Chloro-1- methyl-8-(1- pyridin-2- ylmethyl-1H- pyrazol-4-yl)-9H-pyrido[3,4- b]indole LC4 1.32 374.2 [M + H]⁺ 243

6-Chloro-8-(4- methanesulfinyl- phenyl)-1-methyl- 9H-pyrido[3,4-b]indole LC4 1.27 355.1 [M + H]⁺ 244

6-Chloro-9-ethyl- 1-methyl-8-(1- pyridin-2- ylmethyl-1H-pyrazol-4-yl)-9H- pyrido[3,4- b]indole LC4 1.34 402.2 [M + H]⁺ 245

8-(3-Bromo-2- fluoro-pyridin-4- yl)-6-chloro-1- methyl-9H- pyrido[3,4-b]indole LC4 1.44 390.0 [M + H]⁺ 246

6-Chloro-9-ethyl- 1-methyl-8-(4- phenoxy-phenyl)- 9H-pyrido[3,4-b]indole LC4 1.74 413.2 [M + H]⁺ 247

6-Chloro-1- methyl-8-(3- morpholin-4-yl- phenyl)-9H- pyrido[3,4-b]indole LC4 1.48 378.2 [M + H]⁺ 248

2-[3-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-phenyl]- ethanolLC4 1.39 337.2 [M + H]⁺ 249

6-Chloro-1- methyl-8-[3-(2- morpholin-4-yl- ethoxy)-phenyl]-9H-pyrido[3,4- b]indole LC4 1.11 422.1 [M + H]⁺ 250

3-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)- benzaldehyde LC41.40 321.2 [M + H]⁺ 251

8-(3,5-Bis- trifluoromethyl- phenyl)-6-chloro- 1-methyl-9H- pyrido[3,4-b]indole LC4 1.69 429.1 [M + H]⁺ 252

6-Chloro-1- methyl-8-(4- trifluoromethyl- phenyl)-9H- pyrido[3,4-b]indole LC4 1.60 361.1 [M + H]⁺ 253

6-Chloro-9-ethyl- 1-methyl-8-(3- morpholin-4-yl- phenyl)-9H- pyrido[3,4-b]indole LC4 1.54 406.3 [M + H]⁺ 254

6-Chloro-9-ethyl- 1-methyl-8-(3- morpholin-4- ylmethyl-phenyl)-9H-pyrido[3,4- b]indole LC4 1.06 420.3 [M + H]⁺ 255

6-Chloro-1- methyl-8-(3- morpholin-4- ylmethyl-phenyl)- 9H-pyrido[3,4-b]indole LC4 1.01 392.2 [M + H]⁺ 256

6-Chloro-9-ethyl- 1-methyl-8-[4-(3- methyl-oxetan-3- ylmethoxy)-phenyl]-9H- pyrido[3,4- b]indole LC4 1.57 421.3 [M + H]⁺ 257

6-Bromo-9-ethyl- 1-methyl-8-[4-(3- methyl-oxetan-3- ylmethoxy)-phenyl]-9H- pyrido[3,4- b]indole LC4 1.63 465.1 [M + H]⁺ 258

[3-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-phenyl]-pyridin-2-yl- methanol LC4 1.29 398.1 [M − H]⁻ 259

6-Bromo-1- methyl-8-[4-(2- pyrazol-1-yl- ethoxy)-phenyl]- 9H-pyrido[3,4-b]indole LC4 1.49 447.3 [M + H]⁺ 260

6-Chloro-1- methyl-8-[3- (quinolin-2- ylmethoxy)- phenyl]-9H-pyrido[3,4- b]indole LC4 1.61 450.3 [M + H]⁺ 261

6-Bromo-9-ethyl- 1-methyl-8-(1- pyridin-2- ylmethyl-1H-pyrazol-4-yl)-9H- pyrido[3,4- b]indole LC4 1.34 446.3 [M + H]⁺ 262

6-Chloro-1- methyl-8-(4- trifluoromethoxy- phenyl)-9H- pyrido[3,4-b]indole LC4 1.61 377.2 [M + H]⁺ 263

Acetic acid 2-[4- (6-chloro-9-ethyl- 1-methyl-9H- pyrido[3,4-b]indol-8-yl)-pyrazol-1-yl]- ethyl ester LC14 0.83 397.2 [M + H]⁺ 264

4-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-N-(2- dimethylamino-ethyl)-benzamide LC4 1.03 407.2 [M + H]⁺ 265

3-(6-Chloro-1- methyl-9H- pyrido[3,4-b]indol- 8-yl)-N-(2- dimethylamino-ethyl)-benzamide LC4 1.01 407.2 [M + H]⁺ 266

6-Chloro-1- methyl-8-[4- (pyrimidin-2- ylmethoxy)- phenyl]-9H-pyrido[3,4- b]indole LC4 1.38 401.2 [M + H]⁺ 267

6-Chloro-1- methyl-8-[3- (pyrimidin-2- ylmethoxy)- phenyl]-9H-pyrido[3,4- b]indole LC4 1.42 401.2 [M + H]⁺ 268

8-[4-(5-Bromo- pyrimidin-2- yloxy)-phenyl]-6- chloro-1-methyl-9H-pyrido[3,4- b]indole LC4 1.53 465.2 [M + H]⁺ 269

6-Chloro-8-[3- (isoquinolin-1- ylmethoxy)- phenyl]-1-methyl-9H-pyrido[3,4- b]indole LC4 1.57 450.2 [M + H]⁺ 270

6-Chloro-8-[4- (isoquinolin-1- ylmethoxy)- phenyl]-1-methyl-9H-pyrido[3,4- b]indole LC4 1.57 450.2 [M + H]⁺ 271

6-Chloro-1- methyl-8-[3-(1- methyl-1H- imidazol-2- ylmethoxy)-phenyl]-9H- pyrido[3,4- b]indole LC4 1.14 401.2 [M − H]⁻ 272

6-Chloro-8-[3- (4,6-dimethoxy- pyrimidin-2- ylmethoxy)-phenyl]-1-methyl- 9H-pyrido[3,4- b]indole LC4 1.58 461.2 [M + H]⁺ 273

6-Chloro-1- methyl-8-[3- (thiazol-2- ylmethoxy)- phenyl]-9H- pyrido[3,4-b]indole LC4 1.51 406.2 [M + H]⁺ 274

6-Chloro-1- methyl-8-[3- (quinazolin-2- ylmethoxy)- phenyl]-9H-pyrido[3,4- b]indole LC4 1.51 451.4 [M + H]⁺ 275

6-Chloro-8-[4- (4,6-dimethoxy- pyrimidin-2- ylmethoxy)-phenyl]-1-methyl- 9H-pyrido[3,4- b]indole LC4 1.58 461.3 [M + H]⁺ 276

6-Chloro-8-(1- [1,3]dioxolan-2- ylmethyl-1H- pyrazol-4-yl)-9-ethyl-1-methyl- 9H-pyrido[3,4- b]indole LC4 1.30 397.2 [M + H]⁺ 277

6-Chloro-1- methyl-8-[3-(5- trifluoromethyl- furan-2- ylmethoxy)-phenyl]-9H- pyrido[3,4- b]indole LC8 4.01 457.3 [M + H]⁺ 278

6-Chloro-8-[4- (2,3-dihydro- benzo[1,4]dioxin- 2-ylmethoxy)-phenyl]-1-methyl- 9H-pyrido[3,4- b]indole LC4 1.66 457.3 [M + H]⁺ 279

6-Chloro-8-(6- chloro-pyridin-3- yl)-9- cyclobutylmethyl- 9H-pyrido[3,4-b]indole LC6 1.08 382.1 [M + H]⁺ 280

6-Chloro-9- cyclopropylmethyl- 8-pyridin-3-yl-9H- pyrido[3,4- b]indoleLC6 0.92 334.1 [M + H]⁺ 281

6-Chloro-9- cyclopropylmethyl- 1-methyl-8- pyrimidin-5-yl-9H-pyrido[3,4- b]indole LC8 2.82 349.2 [M + H]⁺ 282

6-Chloro-9- cyclopropylmethyl- 8-(2,4-dichloro- phenyl)-1-methyl-9H-pyrido[3,4- b]indole LC6 1.24 415.1 [M + H]⁺ 283

6-Chloro-8-(4- chloro-pyridin-3- yl)-9- cyclopropylmethyl- 1-methyl-9H-pyrido[3,4- b]indole LC6 1.08 382.1 [M + H]⁺ 284

6-Chloro-8-(2- chloro-pyridin-3- yl)-9- cyclopropylmethyl- 1-methyl-9H-pyrido[3,4- b]indole LC6 1.11 382.1 [M + H]⁺ 285

6-Chloro-9- cyclopropylmethyl- 8-(2,6-dichloro- pyridin-3-yl)-1-methyl-9H- pyrido[3,4- b]indole LC6 1.17 416.1 [M + H]⁺ 286

[5-(6-Chloro-9- cyclopropylmethyl- 1-methyl-9H- pyrido[3,4-b]indol-8-yl)-pyrimidin-2- yl]-dimethyl-amine LC8 3.45 392.2 [M + H]⁺ 287

6-Chloro-9- cyclopropylmethyl- 8-(1-methyl-1H- pyrazol-4-yl)-9H-pyrido[3,4- b]indole LC3 1.03 337.1 [M + H]⁺ 288

6-Chloro-9- cyclopropylmethyl- 8-(1-pyridin-3- ylmethyl-1H-pyrazol-4-yl)-9H- pyrido[3,4- b]indole LC4 1.46 414.2 [M + H]⁺ 289

6-Chloro-9- cyclopropyl-8-(4- methoxy-phenyl)- 9H-pyrido[3,4- b]indoleLC4 1.59 349.2 [M + H]⁺ 290

6-Chloro-9- cyclopropylmethyl- 1-methyl-8-(1- pyridin-3- ylmethyl-1H-pyrazol-4-yl)-9H- pyrido[3,4- b]indole LC4 1.46 428.3 [M + H]⁺ 291

6-Chloro-8-(4- chloro-phenyl)-9- cyclopropylmethyl- 9H-pyrido[3,4-b]indole LC4 1.75 367.3 [M + H]⁺ 292

2-(6-Chloro-9- cyclopropylmethyl- 1-methyl-9H- pyrido[3,4-b]indol-8-yl)-benzamide LC4 1.52 390.2 [M + H]⁺ 293

6-Chloro-9- cyclopropylmethyl- 8-(4-methoxy- phenyl)-1-methyl-9H-pyrido[3,4- b]indole LC8 3.88 377.2 [M + H]⁺ 294

[6-Chloro-5-(6- chloro-9- cyclopropylmethyl- 9H-pyrido[3,4-b]indol-8-yl)- pyridin-2-yl]- dimethyl-amine LC4 1.85 411.1 [M + H]⁺

(a) Isolated in the form of6-chloro-1-methyl-8-(4-phenoxy-phenyl)-9H-pyrido[3,4-b]indolehydrochloride

Exemplary ¹H NMR data of example compounds

Example 6

¹H NMR (400 MHz, DMSO-d₆): δ (ppm)=8.45 (d, 1H), 8.41 (dd, 1H), 8.27 (d,1H), 8.10 (d, 1H), 8.06 (d, 1H), 7.42-7.46 (m, 2H), 7.25 (dd, 1H), 6.68(d, 1H), 5.52 (s, 2H), 4.29 (q, 2H), 2.89 (s, 3H), 2.55 (s, 3H), 0.68(t, 3H)

Example 7

¹H NMR (400 MHz, DMSO-d₆): δ (ppm)=8.54 (d, 1H), 8.31 (d, 1H), 8.17 (t,1H), 8.13 (d, 1H), 7.74 (d, 1H), 7.27 (d, 1H), 6.88 (d, 2H), 6.69 (d,1H), 5.16-5.28 (m, 1H), 5.04-5.15 (m, 1H), 4.13 (br s, 1H), 3.37 (br s,1), 2.85 (s, 3H), 2.06 (s, 3H), 0.80 (t, 3H)

Example 8

¹H NMR (400 MHz, DMSO-d₆): δ (ppm)=11.14 (s, 1H), 8.26 (d, 1H), 8.01 (d,1H), 7.54-7.75 (m, 2H), 7.46 (s, 1H), 7.16-7.21 (m, 2H), 4.53 (d, 2H),4.36 (d, 2H), 4.16 (s, 2H), 2.90 (s, 3H), 2.79 (s, 3H), 1.41 (s, 3H)

Example 10

¹H NMR (400 MHz, DMSO-d₆): δ (ppm)=9.22 (s, 1H), 8.48-8.53 (m, 2H), 8.28(d, 1H), 8.04 (s, 1H), 7.71 (s, 1H), 7.42 (d, 1H), 5.21 (q, 2H), 4.95(t, 1H), 4.26 (t, 2H), 3.80 (q, 2H)

Example 13

¹H NMR (400 MHz, DMSO-d₆): δ (ppm)=11.17 (s, 1H), 8.31 (d, 1H), 8.23 (d,1H), 8.01 (d, 1H), 7.84 (d, 1H), 7.62-7.68 (m, 2H), 7.49 (d, 1H), 7.43(d, 1H), 7.10-7.15 (m, 2H), 6.28 (t, 1H), 4.56 (t, 2H), 4.44 (t, 2H),2.77 (s, 3H)

Example 21

¹H NMR (400 MHz, DMSO-d₆): δ (ppm)=15.26 (br s, 1H), 8.74 (d, 1H), 8.59(s, 1H), 8.11 (s, 1H), 7.76 (s, 1H), 7.67 (d, 1H), 4.41 (q, 2H), 3.96(s, 3H), 3.18 (s, 3H), 2.80 (s, 3H), 0.89 (t, 3H)

Example 22

¹H NMR (400 MHz, DMSO-d₆): δ (ppm)=8.61-8.73 (m, 2H), 8.51 (br d, 1H),7.58 (d, 1H), 7.49-7.54 (m, 2H), 7.10-7.15 (m, 2H), 3.86 (s, 3H), 3.68(s, 3H), 3.14 (s, 3H)

Example 27

¹H NMR (400 MHz, DMSO-d₆): δ (ppm)=12.31 (br s, 1H), 8.57 (d, 1H), 8.48(d, 1H), 7.60-7.74 (m, 3H), 7.13-7.21 (m, 2H), 3.87 (s, 3H), 3.05 (s,3H), 2.98 (s, 3H)

Example 33

¹H NMR (600 MHz, DMSO-d₆): δ (ppm)=12.66 (br s, 1H), 9.11 (s, 1H), 8.70(br d, 1H), 8.59 (d, 1H), 8.01 (d, 1H), 7.68-7.73 (m, 2H), 7.18-7.21 (m,2H), 3.88 (s, 3H), 3.06 (s, 3H)

Example 39

¹H NMR (400 MHz, DMSO-d₆): δ (ppm)=11.18 (s, 1H), 8.31 (d, 1H), 8.24 (d,1H), 8.01 (d, 1H), 7.68 (m, 2H), 7.44 (d, 1H), 7.27-7.33 (m, 2H), 7.22(s, 1H), 6.91 (s, 1H), 5.25 (s, 2H), 3.73 (s, 3H), 2.78 (s, 3H)

Example 45

¹H NMR (400 MHz, DMSO-d₆): δ (ppm)=11.11 (br s, 1H), 8.25 (d, 1H), 8.00(d, 1H), 7.83 (d, 1H), 7.58-7.64 (m, 2H), 7.48 (d, 1H), 7.44 (s, 1H),7.08-7.14 (m, 2H), 6.27 (t, 1H), 4.56 (t, 2H), 4.44 (t, 2H), 2.89 (s,3H), 2.78 (s, 3H)

Example 46

¹H NMR (400 MHz, DMSO-d₆): δ (ppm)=9.11 (s, 1H), 8.61 (d, 1H), 8.46 (d,1H), 8.32 (d, 1H), 8.27 (d, 1H), 7.82 (d, 1H), 7.54 (d, 1H), 4.07 (dd,1H), 3.76 (dd, 1H), 0.69-0.80 (m, 1H), −0.17-0.28 (m, 2H), 0.03-0.16 (m,2H)

Example 55

¹H NMR (500 MHz, DMSO-d₆): δ (ppm)=9.47 (s, 1H), 8.85 (d, 1H), 8.77 (d,1H), 8.69 (br d, 1H), 8.33 (d, 1H), 7.84 (d, 1H), 7.76 (d, 1H),4.18-4.36 (m, 1H), 3.74-3.95 (m, 1H), 0.99 (t, 3H)

Example 116

¹H NMR (400 MHz, DMSO-d₆): δ (ppm)=8.58 (d, 1H), 8.54 (dd, 1H), 8.40 (d,1H), 8.29 (s, 1H), 8.28 (d, 1H), 8.10 (d, 1H), 7.82 (s, 1H), 7.69-7.74(m, 1H), 7.40-7.46 (m, 1H), 7.38 (d, 1H), 5.51 (s, 2H), 4.34 (q, 2H),2.91 (s, 3H), 0.74 (t, 3H)

Example 148

¹H NMR (400 MHz, DMSO-d₆): δ (ppm)=8.81 (d, 1H), 8.77 (d, 1H), 8.60 (brd, 1H), 7.62-7.68 (m, 4H), 7.61 (d, 1H), 4.18 (q, 2H), 3.12 (s, 3H),0.86 (t, 3H)

Example 149

¹H NMR (500 MHz, DMSO-d₆): δ (ppm)=12.45 (s, 1H), 8.71 (d, 1H), 8.65 (d,1H), 8.54 (br d, 1H), 7.66-7.72 (m, 3H), 7.15-7.22 (m, 2H), 3.88 (s,3H), 3.06 (s, 3H)

Example 184

¹H NMR (500 MHz, DMSO-d₆): δ (ppm)=11.18 (s, 1H), 8.29 (d, 1H), 8.23 (d,1H), 8.00 (d, 1H), 7.40-7.45 (m, 3H), 6.93 (d, 1H), 4.22 (t, 2H), 2.87(t, 2H), 2.78 (s, 3H), 1.96-2.03 (m, 2H)

Example 209

¹H NMR (400 MHz, DMSO-d₆): δ (ppm)=8.87 (d, 1H), 8.76 (d, 1H), 8.57 (d,1H), 8.11 (s, 1H), 7.76 (d, 1H), 7.68 (d, 1H), 4.45 (q, 2H), 3.97 (s,3H), 3.15 (s, 3H), 0.92 (t, 3H)

Example 215

¹H NMR (400 MHz, DMSO-d₆): δ (ppm)=11.30 (s, 1H), 8.40 (d, 1H), 8.25 (d,1H), 8.08 (d, 1H), 8.03 (d, 1H), 7.48 (d, 1H), 6.75-6.84 (m, 2H), 6.10(s, 2H), 2.79 (s, 3H)

Example 228

¹H NMR (400 MHz, DMSO-d₆): δ (ppm)=11.18 (s, 1H), 8.31 (d, 1H), 8.24 (d,1H), 8.01 (d, 1H), 7.63-7.68 (m, 2H), 7.44 (d, 1H), 7.12-7.16 (m, 2H),3.92-4.00 (m, 2H), 2.78 (s, 3H), 2.53-2.67 (m, 3H), 2.32-2.44 (m, 2H),2.26 (s, 3H), 1.93-2.03 (m, 1H), 1.49-1.58 (m, 1H)

Example 256

¹H NMR (400 MHz, DMSO-d₆): δ (ppm)=8.66-8.78 (m, 2H), 8.54 (d, 1H),7.46-7.59 (m, 3H), 7.14-7.21 (m, 2H), 4.54 (d, 2H), 4.35 (d, 2H), 4.33(q, 2H), 4.16 (s, 2H), 3.10 (s, 3H), 1.42 (s, 3H), 0.84 (t, 3H)

Biologic Examples

A) Chondrogenesis Activity Assay in ATDC5 Cells

The chondrogenic potential of the compounds of the invention wasdetermined using clonal mouse chondrogenic ATDC5 cells (T. Atsumi etal., Cell Differ. Dev. 1990, 30, 109-116). ATDC5 cells are derived frommouse embryonic AT805 teratocarcinoma cells and are used frequently tostudy the multistep chondrogenic differentiation process from precursorcells into chondrocytes (C. Shukunami et al., Exp. Cell Res. 1998, 241,1-11; H. Akiyami et al., J. Bone Miner. Res. 1996, 11, 22-28; H. Akiyamiet al., Biochem. Biophys. Res. Commun. 1997, 235, 142-147; C. Shukunamiet al., J. Cell Biol. 1996, 133, 457-468; C. Shukunami et al., J. BoneMiner. Res. 1997, 12, 1174-1188). Undifferentiated ATDC5 cells grow invitro until confluence, showing a fibroblast-like morphology. In thepresence of insulin, cells undergo transient condensation and formnumerous nodular structures (cartilage nodules). The cartilagenousnature of these nodules was shown by Alcian Blue staining as evidence ofthe production of proteoglycan (aggrecan) and collagen type IIexpression (by expression analysis), both molecular markers ofchondrocytes (C. Shukunami et al., J. Cell Biol. 1996, 133, 457-468).

Chondrogenic differentiation of ATDC5 cells into chondrocytes by thecompounds of the invention was determined by measuring the induction oftype II collagen protein as a marker of chondrocytes, a structuralcomponent of the extracellular matrix which constitutes more than 80% ofcartilage mass (D. R. Eyre, Clin. Orthop. Relat. Res. 2004, 427 Suppl,S118-S122). ATDC5 cells were obtained from RIKEN and cultured asmonolayer in basal culture medium (Dulbecco's Modified EagleMedium/Nutrient Mixture F-12 (DMEM/F12, Invitrogen, #31331-093)supplemented with 10 μg/ml Transferrin (Roche, #10652 202001), 3×10E-8 Msodium selenite (Sigma, #S-5261) and 5% Fetal Calf Serum (FCS Gold, PAA,#A15-251)), at 37° C. and 5% CO₂ in plastic flasks of 75 cm² or 300 cm²subconfluently for propagation. ATDC5 cells were harvested andresuspended in differentiation culture medium that consisted of basalculture medium complemented with 10 μg/ml insulin (Sigma, #19278), toinitiate chondrogenic differentiation. For studying the effect of testcompounds, the ATDC5 cells were plated in 96-well plates (3.0×10E4 cellsper well in 200 μl of differentiation culture medium). Test compoundsdissolved in DMSO were added to yield increasing compoundconcentrations, typically from 40 nM to 10 μM, and a final DMSOconcentration of 0.1%. On each 96-well plate, control wells containingno test compound but the same concentration of DMSO, i.e. untreatedcells, were included and used as reference for the determination of theeffect of the test compounds on the cells, and wells containing aninternal reference compound at a concentration of 10 μM were includedand used as positive control and for standardizing the results. Cells inthe wells were incubated for 4 days at 37° C. and 5% CO₂, followed byquantification of intracellular collagen type II.

Quantification of collagen type II in the ATDC5-cells was done byimmunofluorescence staining of collagen type II, and fluorescenceintensity was measured using a cellular high content imaging system(ImageXpress, Molecular Device). For immunofluorescence staining ofintracellular collagen, medium was removed after compound incubation andcells were fixed with 200 μl/well methanol/water (95%/5%). Cells werepermeabilized in 200 μl/well phosphate-buffered saline (PBS) containing0.2% Triton X100 for 15 min and, after removal of the solution, blockedfor 30 min with 200 μl/well PBS/0.2% Triton X100 containing 1 bovineserum albumin (BSA) to avoid unspecific binding. After the blockingstep, the solution was removed and collagen type II staining solutionwas added. A primary antibody mouse anti-collagen type II solution(Quartett Immundiagnostika, #031502302) was diluted 1:100 in PBS/1% BSA,and 50 μl of the solution was added to each well and incubated for 1hour at room temperature. After washing three times with PBS, 50 μl perwell of a second antibody solution was added and incubated for 1 hour.The second antibody solution contained PBS/1% BSA with a 1:250 dilutionof goat anti-mouse IgG (H+L) antibody coupled with fluorescent dye AlexaFluor 488 (Invitrogen, #A11029), and fluorescent dye Hoe 33342 forstaining nuclei with a final concentration of 2 μg/ml. Fluorescencesignal intensity was measured for fluorescent dye Alexa Fluor 488 andfor dye Hoe 33342, and the signals integrated over 9 fields within eachwell of a 96-well plate.

The change of the collagen type II-derived fluorescence signal intensitywas calculated for each compound concentration relative to the control(untreated cells, i.e. no test compound added), and an EC₅₀ value(effective concentration 50 (in μM (micromol/liter)), i.e. the compoundconcentration at which the effect of the compound on collagen type IIinduction reaches 50% of the maximum induction) was calculated using asigmoidal signal fit procedure. To allow the comparison of compoundactivities determined in different experiments, given the naturalbiological variation of the chondrogenic response between differentexperiments, an internal reference compound at a concentration of 10 μMwas included in all experiments, and for each concentration collagentype II induction was calculated in percent in relation to the internalreference compound at 10 μM. The maximum percent induction (relative tothe internal reference compound at a concentration of 10 μM) of acompound is termed E_(max). EC₅₀ values (in μM) and E_(max) values (inpercent) obtained for compounds of the invention in this test are givenin Table 2. In Table 2 the E_(max) value “a” denotes a maximum percentinduction of less than 20%, the E_(max) value “b” denotes a maximumpercent induction from 20% to less than 50%, the E_(max) value “c”denotes a maximum percent induction from 50% to less than 80%, and theE_(max) value “d” denotes a maximum percent induction of more than 80%,in each case relative to the internal reference compound at aconcentration of 10 μM.

TABLE 2 Example no. EC₅₀ [μM] E_(max) 1 1.7 a 2 0.71 d 3 >10 b 4 0.83 d5 0.49 d 6 2.2 c 7 >3.3 a 8 0.12 d 9 1.4 d 10 0.69 d 11 3.9 c 12 >10 b13 0.12 d 14 0.86 d 15 1.0 c 16 2.8 c 17 3.6 d 18 1.0 d 19 >10 c 20 3.9c 21 >3.3 b 22 0.63 d 23 1.5 c 24 2.0 c 25 0.17 d 26 0.53 c 27 0.097 d28 0.19 d 29 >1.1 a 30 0.27 d 31 0.25 d 32 0.37 c 33 0.12 d 34 >1.1 b 353.1 d 36 0.10 d 37 >3.3 b 38 2.6 c 39 0.17 d 40 0.15 d 41 0.24 c 42 0.51c 43 >6.6 a 44 0.67 d 45 0.13 d 46 1.4 d 47 >10 b 48 0.041 a 49 0.041 a50 0.13 a 51 >10 a 52 1.2 c 53 2.1 c 54 1.1 b 55 0.65 d 56 0.46 b 57 1.6a 58 1.5 b 59 1.3 d 60 2.5 b 61 5.6 d 62 1.2 d 63 0.59 b 64 3.9 d 65 2.3b 66 2.1 c 67 0.74 b 68 7.6 c 69 2.0 c 70 0.57 d 71 1.5 a 72 5.8 b 730.44 b 74 0.92 b 75 1.5 b 76 >10 b 77 0.58 d 78 >10 a 79 3.9 d 80 1.2 b81 4.1 d 82 2 b 83 2.1 b 84 >10 b 85 >10 b 86 0.75 d 87 1.5 c 88 1.7 a89 >10 d 90 >10 a 91 1.5 d 92 2.5 d 93 2.2 d 94 0.75 d 95 0.58 c 96 0.85c 97 >1.1 a 98 2.4 d 99 >10 a 100 1.0 a 101 8.2 b 102 2.1 b 103 1.9 d104 3.5 d 105 1.0 c 106 >10 b 107 0.56 b 108 1.4 d 109 0.72 c 110 >10 b111 1.8 c 112 0.49 d 113 0.78 d 114 5.7 b 115 0.49 d 116 0.39 d 117 >10a 118 >1.1 b 119 >3.3 a 120 1.4 c 121 0.59 d 122 >3.3 b 123 0.26 b 1242.6 a 125 1.0 d 126 >10 b 127 0.38 c 128 3.9 a 129 0.86 d 130 0.38 d 1310.78 d 132 4.5 b 133 >10 b 134 >10 a 135 0.33 c 136 4.1 c 137 1.4 b138 >10 a 139 >10 a 140 0.91 b 141 >10 a 142 0.52 d 143 0.97 b 144 0.58a 145 0.48 a 146 0.041 a 147 0.84 d 148 0.046 d 149 0.33 d 150 0.51 d151 0.54 c 152 0.35 a 153 4.5 c 154 8.8 b 155 >3.3 a 156 1.5 a 157 >10 b158 1.9 d 159 1.3 c 160 >10 a 161 2.0 d 162 0.59 d 163 0.69 d 164 0.23 d165 >10 a 166 0.84 d 167 >10 b 168 0.99 d 169 1.1 d 170 >10 b 171 1.9 d172 >10 b 173 1.9 d 174 7.3 c 175 >10 a 176 >10 b 177 >10 b 178 >10 b179 >10 d 180 0.33 d 181 2.1 d 182 0.22 d 183 2.3 c 184 3.0 c 185 >10 b186 0.10 d 187 2.2 d 188 0.64 d 189 0.50 d 190 0.72 d 191 0.55 d 1920.64 d 193 >10 b 194 0.14 d 195 >10 a 196 0.80 c 197 0.63 d 198 1.8 b199 >10 a 200 >10 b 201 0.60 d 202 0.64 d 203 >10 a 204 0.19 c 205 3.3 d206 >10 b 207 1.6 d 208 1.9 d 209 0.28 d 210 >3.3 a 211 >3.3 a 212 >3.3a 213 >1.1 a 214 >3.3 a 215 0.23 d 216 >10 a 217 >3.3 b 218 >1.1 a219 >3.3 a 220 >10 b 221 >3.3 b 222 >10 a 223 >3.3 b 224 0.31 d 225 1.7d 226 0.19 c 227 0.33 d 228 0.15 c 229 0.28 c 230 >3.3 a 231 >10 b 2320.33 d 233 >10 b 234 5.8 c 235 >3.3 b 236 >3.3 a 237 0.50 d 238 1.4 d239 0.25 c 240 0.49 c 241 >1.1 b 242 0.57 d 243 0.66 d 244 1.1 d245 >1.1 a 246 2.9 c 247 >3.3 a 248 >3.3 b 249 >3.3 b 250 >3.3 c 251 >10a 252 1.6 d 253 >10 b 254 >3.3 a 255 >3.3 a 256 0.16 d 257 0.31 d258 >3.3 a 259 0.43 d 260 >1.1 a 261 1.5 d 262 2.3 d 263 0.55 d 264 >1.1b 265 >1.1 a 266 0.11 d 267 >3.3 c 268 0.34 d 269 >3.3 b 270 >1.1 b271 >3.3 b 272 1.9 d 273 0.17 a 274 >3.3 a 275 0.30 d 276 0.42 d277 >3.3 a 278 >3.3 b 279 1.8 b 280 >10 a 281 0.11 a 282 3.6 a 283 0.41a 284 4.2 a 285 6.1 b 286 0.041 a 287 0.23 c 288 0.52 d 289 0.75 d290 >10 b 291 1.7 c 292 >6.6 a 293 4.5 c 294 1.2 d

B) Chondrogenesis activity assay in primary human chondrocyte pelletcultures

In this assay human articular chondrocytes are harvested by enzymaticdigestion from articular cartilage and passaged several times todedifferentiate the chondrocytes and to propagate the cells. Cells arecultured as cell pellets in the presence of the compounds of theinvention over 2 weeks, and the chondrogenic differentiation isquantified by the production of the chondrogenic marker aggrecan(proteoglycan).

In detail, primary chondrocytes were harvested by enzymatic digestionfrom cartilage of osteoarthritis patients undergoing knee jointreplacement surgery, and cultured in vitro. Cells were passaged one ortwo times and aliquots were cryopreserved. To initiate chondrogenesisexperiments, cell aliquots were thawn, cultured in Chondrocyte GrowthMedium (CGM, Lonza, #CC-3216) and passaged twice to further propagateand dedifferentiate cells. Pellet cultures were initiated by seeding2.5×10E5 cells per well into a 96-well deep well plate in 600 μlchondrocyte differentiation medium consisting of Dulbecco's ModifiedEagle Medium (DMEM, Invitrogen, #41966), 1×ITS-solution(Insulin/Transferrin/sodium selenite; 100× solution: Invitrogen,#51500056), 5 μg/mL linoleic acid (Sigma, #L1012-1G), 1× nonessentialamino acids (100× solution: Invitrogen, #11140); 10 nM Dexamethasone, 2ng/ml TGF-β1 (transforming growth factor β1) and 10 μg/ml ascorbic acid.Cells were spun to pellets by centrifugation (10 min, 400×g). Testcompounds dissolved in DMSO were added to yield increasing compoundconcentrations, typically from 40 nM to 10 μM, and a final DMSOconcentration of 0.1%, and the cell pellets cultured at 37° C. and 5%CO₂ for 2 weeks. On each 96-well plate, control wells containing no testcompound but the same concentration of DMSO, i.e. untreated cells, wereincluded and used as reference for the determination of the effect ofthe test compounds on the cells, and wells containing an internalreference compound at a concentration of 10 μM were included and used aspositive control and for standardizing the results. Chondrocytedifferentiation medium and the compounds were exchanged twice weeklyuntil harvest of the pellets.

For harvest of the pellets, medium was removed and the pellet washomogenized by enzymatic digestion. 100 μl of protease solutioncontaining 0.4 mg/ml papain, 50 mM sodium phosphate, 4 mM EDTA and 0.48mg/ml L-cysteine was added to the pellet in each well of a 96-wellplate, the plate was sealed with a plate sealer foil (SILVERseal,Greiner Bio-One) and incubated for 4 to 6 hours at 65° C. withagitation. The concentration of proteoglycan (aggrecan) was determinedby quantification of the sulfated glycosaminoglycan side chains ofaggrecan using the Blyscan assay (Kit from Biocolor). Aliquots of thepapain-digest were transferred to 400 μl of Blyscan dye solution andincubated at room temperature for 45 min with agitation (1200 rpm). Themixture was centrifuged at 3760×g for 45 min, the supernatant wasdiscarded, and the stained pellet was redissolved in 400 μl of Blyscandissociation reagent by rotation until the precipitate completelyresolved. Optical density was measured at 656 nm using a Tecan Saphire2instrument, and the amount of proteoglycan determined against a standardcurve with chondroitin-4-sulfate.

Induction of proteoglycan (aggrecan) was calculated for each compoundconcentration relative to the control (untreated cells, i.e. no testcompound added), and an EC₅₀ value (effective concentration 50 (in μM(micromol/liter)), i.e. the compound concentration at which the effectof the compound on proteoglycan (aggrecan) induction reaches 50% of themaximum induction) was calculated using a sigmoidal signal fitprocedure. To allow the comparison of compound activities determined indifferent experiments, given the natural biological variation of thechondrogenic response between different experiments, an internalreference compound at a concentration of 10 μM was included in allexperiments, and for each concentration proteoglycan (aggrecan)induction was calculated in percent in relation to the internalreference compound at 10 μM. The maximum percent induction (relative tothe internal reference compound at a concentration of 10 μM) of acompound is termed E_(max). EC₅₀ values (in μM) and E_(max) values (inpercent) obtained for compounds of the invention in this test are givenin Table 3. In Table 3 the E_(max) value “a” denotes a maximum percentinduction of less than 40%, the E_(max) value “b” denotes a maximumpercent induction from 40% to less than 100%, the E_(max) value “c”denotes a maximum percent induction from 100% to less than 200%, and theE_(max) value “d” denotes a maximum percent induction of more than 200%,in each case relative to the internal reference compound at aconcentration of 10 μM.

TABLE 3 Example no. EC₅₀ [μM] E_(max) 2 4.4 d 5 1.3 d 8 0.26 c 10 2.4 b11 7.9 b 13 1.1 d 19 6.9 b 21 4.3 d 22 4.0 d 27 3.5 d 29 1.5 c 33 0.83 c34 3.8 d 37 4.3 c 39 3.7 d 45 0.22 b 46 1.0 c 55 0.95 c 97 5.1 d 116 1.3c 117 27 a 118 1.3 c 119 21 b 122 3.6 c 149 1.1 c 167 13 a 171 4.0 d 1841.9 b 194 0.83 c 195 14 a 199 22 a 200 4.4 c 206 19 a 209 2.6 d 212 8.9a 213 1.2 c 214 1.3 c 215 0.99 d 217 4.9 d 218 40 a 223 27 a 228 0.14 c230 21 a 235 5.1 d 236 4.6 d 241 1.5 c 244 4.9 d 245 10 b 247 3.8 d 2504.9 c 251 9.1 b 256 1.3 d 258 8.2 b 264 1.5 b 265 3.8 a 270 4.3 b 2714.9 d 288 1.2 d

The compounds of the invention can also be tested in the animal modelsdescribed in biological examples C) and D), which are in vivo models ofosteoarthritis (OA) in rodents.

C) Joint instability induced OA in rats after anterior cruciate ligamenttransection and partial meniscectomy (ACLT-pMx)

In this model osteoarthritis is induced via ACLT-pMx surgery in rats andassessment of histopathological joint damage is conducted as primaryreadout. Under general anesthesia by isoflurane (4%-5% in 3 L/min O₂)the right leg of the rats is shaved and disinfected with Cutasept®(Beiersdorf, Germany). Then, with the leg in extension, a para-patellarskin incision is made on the medial side of the joint. After dislocatingthe patella laterally, an incision of the joint capsule on the medialside of the patellar tendon is made to access the joint space. Theanterior cruciate ligament is transected using a modified sharpened hook(“Ohrhebel nach Wagener”; Aesculap, #OF 285 R). Then the medial meniscusis gently retracted and the cranial part of the meniscus (30%) carefullyexcised by using an Aesculap microscalpel to ensure that the cartilageof the femur and the tibia is not damaged. During the surgery the jointspace is lavaged with 0.9% sterile saline to remove all blood from thejoint and to prevent damage by drying of the tissue. After repositioningof the patella the joint capsule is closed with Safil® absorbablesutures (B. Braun Melsungen, Germany). The skin is closed with Dafilon®3/0 sutures (B. Braun Melsungen, Germany). Buprenorphine hydrochlorideis given subcutaneously (0.06 mg/kg) as a post-surgical analgesictreatment.

Treatment onset with a test compound is seven days after surgery. Theanimals receive intra-articular injections of 0.1 to 1 mg/joint of thetest compound suspended in 50 μl of vehicle into the operated knee jointin up to weekly intervals, whereas the control animals receiveinjections of 50 μl of the vehicle. At day 28 post surgery all animalsare sacrificed for histology and histopathological analysis, which isperformed as described in biological example D).

D) Spontaneous model of OA in Dunkin Hartley guinea pigs

In this model Dunkin Hartley guinea pigs of strain HsdDhl:DH (HarlanLaboratories, The Netherlands), which is a widely used strain forspontaneous animal models of OA since their histological and biochemicalchanges resemble that of human OA (A. M. Bendele et al., ArthritisRheum. 1988, 31, 561-565), are used at the age of 6 months. It is knownthat histological changes start at the age of about 3 months and diseaseseverity increases with age (P. A. Jimenez et al., Lab. Anim. Sci. 1997,47, 598-601). Therefore treatment onset in this model is at the age of 6months and continued until animals reach an age of a minimum of 12months.

The animals receive intra-articular injections of 0.1 to 3 mg/joint ofthe test compound suspended in 100 μl of vehicle into the right kneejoint in up to weekly intervals, whereas the control animals receiveinjections of 100 μl of the vehicle. After a minimum of 6 monthstreatment all animals are sacrificed for histology and histopathologicalanalysis.

Evaluation of the tests described in examples C) and D) is done in thefollowing way.

For histological processing of the tissue the right knee joints of theanimals are excised at the mid-shaft of femur and tibia and placed in10% formalin for 3 days, to fix the tissue. After fixing the knees aredecalcified in formic acid (Immunocal®, Decal Chemical Corp., NY, USA)for 11 days, dehydrated in the Tissue Processor TP 1020® (Leica,Germany) and embedded in paraffin. The paraffin-embedded complete kneeis serially sectioned (coronal sections) on a rotary microtome at athickness of 7 μm and the sections are stained with Hematoxylin/Eosin(H&E) or Safranin O/Fast Green (SO). For each knee 4 subregions of theknee joint (medial or lateral tibia or femur) are defined. From eachsubregion 5 sections with the most severe damage are selected andevaluated by two observers blinded to the treatment by using a modifiedMankin score.

Digital images from histological H&E-stained as well as SO-stainedcoronal sections of the whole knee joint are taken using a ZeissAxioScanner®. After conversion into tif files and transfer into thedigital image analysis software Visiopharm Integrator System (VIS;Version Nr. 3.0.15.0; Visiopharm, Denmark), the cartilage tissue, thechondrocytes, the SO-stained cartilage area and the subchondral bone aresegmented. As region of interest (ROI) a rectangle of 1.2×0.5 mmcovering the most affected area of cartilage and the underlyingsubchondral bone in the medialtibial plateau are chosen. The degree ofcartilage destruction and subchondral bone sclerosis is then quantifiedby measuring the following parameters: fibrillation index (FI; the widthof the region of interest (box) divided by the cartilage surfacecurvature length, i.e. measures of cartilage surface irregularity);cartilage area; chondrocyte number (cell number per residual cartilagearea); absolute number of residual chondrocytes; proteoglycan containing(SO-stained) cartilage area; subchondral solid bone area.

For statistical analysis of the data, results are given as median,inter-quartile and complete data range (histopathological scoring) ormean±SEM (histomorphometry). The statistical significance of the effectof a compound on the histomorphometrically assessed joint pathology isdetermined by a one way analysis of variance followed by Dunnett's testfor multiple comparisons versus the vehicle-treated group.Kruskal-Wallis test and multiple comparisons by Dunn's Test versus thevehicle-treated group are applied for the semi-quantitativehistopathological scores. SAS® v8.2 via Everstat software v5.0 interfaceis used for the statistical analyses.

The invention claimed is:
 1. A compound of formula I

or a pharmaceutically acceptable salt thereof, wherein: A is selectedfrom the group consisting of phenyl and a monocyclic or bicyclic,5-membered to 10-membered, aromatic heterocyclic group, wherein thearomatic heterocyclic group comprises 1 or 2 identical or differenthetero ring members selected from the group consisting of N, N(R²⁰), Oand S, and is bonded via a ring carbon atom, and wherein the phenyl andthe aromatic heterocyclic group are unsubstituted or substituted on ringcarbon atoms by one or more identical or different substituents R²¹; Eis a direct bond or a chain consisting of 1 to 5 chain members of which0, 1 or 2 chain members are identical or different hetero chain membersselected from the group consisting of N(R²⁵), O and S(O)_(m), and theother chain members are identical or different groups C(R²⁶)(R²⁷); G isselected from the group consisting of hydrogen, halogen, (C1-C4)-alkyl,cyano and R³⁰; R¹, R³, R⁴ and R⁶ are independently selected from thegroup consisting of hydrogen, halogen and (C₁-C₄)-alkyl; R² is selectedfrom the group consisting of hydrogen, halogen, (C₁-C₄)-alkyl and(C₁-C₄)-alkyl-O—C(O)—; R⁵ is selected from the group consisting ofhydrogen, halogen, (C₁-C₄)-alkyl, (C₁-C₄)-alkyl-O—, cyano, R⁷—O—C(O)—and R⁸—N(R⁹)—C(O)—; R⁷, R⁸, R⁹, R²⁰, R²², R²⁵, R³¹, R³³, R³⁴ and R⁴⁰ areindependently selected from the group consisting of hydrogen and(C₁-C₄)-alkyl; R¹⁰ is selected from the group consisting of hydrogen,(C₁-C₆)-alkyl, (C₂-C₆)-alkenyl, (C₂-C₆)-alkynyl and (C₃-C₇)-cycloalkyl,wherein the (C₁-C₆)-alkyl group is unsubstituted or substituted by 1 or2 identical or different substituents selected from the group consistingof (C₃-C₇)-cycloalkyl, Het, cyano and (C₁-C₄)-alkyl-O—, and wherein each(C₃-C₇)-cycloalkyl group is unsubstituted or substituted by one or moreidentical or different substituents selected from the group consistingof fluorine and (C₁-C₄)-alkyl; R²¹ is selected from the group consistingof halogen, (C₁-C₄)-alkyl, (C₁-C₄)-alkyl-O— and cyano, or two groups R²¹attached to adjacent ring carbon atoms in group A are taken togetherwith the carbon atoms to which they are attached to form a 5-membered to7-membered mono-unsaturated ring comprising 0, 1 or 2 identical ordifferent hetero ring members selected from the group consisting ofN(R²²), O and S(O)_(m), and which is unsubstituted or substituted onring carbon atoms by one or more identical or different substituentsselected from the group consisting of fluorine and (C₁-C₄)-alkyl; R²⁶and R²⁷ are independently selected from the group consisting ofhydrogen, fluorine, (C₁-C₄)-alkyl and hydroxy, and in one or two groupsC(R²⁶)(R²⁷), the substituents R²⁶ and R²⁷ attached to the same carbonatom are optionally taken together to form oxo; R³⁰ is a monocyclic orbicyclic, 3-membered to 10-membered ring, which is saturated orunsaturated and comprises 0, 1, 2 or 3 identical or different heteroring members selected from the group consisting of N, N(R³¹), O andS(O)_(m), and which is unsubstituted or substituted on ring carbon atomsby one or more identical or different substituents R³²; R³² is selectedfrom the group consisting of halogen, (C₁-C₄)-alkyl, hydroxy, oxo,(C₁-C₄)-alkyl-O—, cyano, R³³—N(R³⁴)— and Het; and m is selected from thegroup consisting of 0, 1 and 2, wherein all numbers m are independent ofeach other and are identical or different; wherein Het is a monocyclic,4-membered to 7-membered, saturated heterocyclic group comprising 1 or 2identical or different hetero ring members selected from the groupconsisting of N, N(R⁴⁰), O and S(O)_(m), and which is unsubstituted orsubstituted on ring carbon atoms by one or more identical or differentsubstituents selected from the group consisting of fluorine and(C₁-C₄)-alkyl; and wherein each alkyl group, independently of any othersubstituents which can be present on an alkyl group, is optionallysubstituted by one or more fluorine substituents, provided that thecompound of formula I is not 8-phenyl-9H-pyrido[3,4-b]indole.
 2. Thecompound of formula I according to claim 1, or a pharmaceuticallyacceptable salt thereof, wherein: A is selected from the groupconsisting of phenyl and a monocyclic, 5-membered or 6-membered,aromatic heterocyclic group, wherein the aromatic heterocyclic groupcomprises 1 or 2 identical or different hetero ring members selectedfrom the group consisting of N, N(R²⁰), O and S, and is bonded via aring carbon atom, and wherein the phenyl and the aromatic heterocyclicgroup are unsubstituted or substituted on ring carbon atoms by one ormore identical or different substituents R²¹; E is a direct bond or achain consisting of 1 to 4 chain members of which 0, 1 or 2 chainmembers are identical or different hetero chain members selected fromthe group consisting of N(R²⁵), O and S(O)_(m), and the other chainmembers are identical or different groups C(R²⁶)(R²⁷); G is selectedfrom the group consisting of hydrogen, halogen, (C₁-C₄)-alkyl and R³⁰;R¹, R³, R⁴ and R⁶ are independently selected from the group consistingof hydrogen, halogen and (C₁-C₃)-alkyl; R² is selected from the groupconsisting of hydrogen, halogen and (C₁-C₃)-alkyl; R⁵ is selected fromthe group consisting of hydrogen, halogen, (C₁-C₄)-alkyl,(C₁-C₄)-alkyl-O— and cyano; R¹⁰ is selected from the group consisting ofhydrogen, (C₁-C₆)-alkyl and (C₃-C₇)-cycloalkyl, wherein the(C₁-C₆)-alkyl group is unsubstituted or substituted by 1 substituentselected from the group consisting of (C₃-C₇)-cycloalkyl, Het, cyano and(C₁-C₄)-alkyl-O—, and wherein each (C₃-C₇)-cycloalkyl group isunsubstituted or substituted by one or more identical or differentsubstituents selected from the group consisting of fluorine and(C₁-C₄)-alkyl; R²⁰, R²², R²⁵, R³¹ and R⁴⁰ are independently selectedfrom the group consisting of hydrogen and (C₁-C₄)-alkyl; R²¹ is selectedfrom the group consisting of halogen, (C₁-C₄)-alkyl, (C₁-C₄)-alkyl-O—and cyano, or two groups R²¹ attached to adjacent ring carbon atoms ingroup A are taken together with the carbon atoms to which they areattached to form a 5-membered or 6-membered mono-unsaturated ringcomprising 0, 1 or 2 identical or different hetero ring members selectedfrom the group consisting of N(R²²), O and S(O)_(m), and which isunsubstituted or substituted on ring carbon atoms by one or moreidentical or different substituents selected from the group consistingof fluorine and (C₁-C₄)-alkyl; R²⁶ and R²⁷ are independently selectedfrom the group consisting of hydrogen, fluorine, (C₁-C₃)-alkyl andhydroxy, and in one group C(R²⁶)(R²⁷), the substituents R²⁶ and R²⁷attached to the same carbon atom together are optionally taken togetherto form oxo; R³⁰ is a monocyclic or bicyclic, 3-membered to 10-memberedring, which is saturated or unsaturated and comprises 0, 1, 2 or 3identical or different hetero ring members selected from the groupconsisting of N, N(R³¹), O and S(O)_(m), and which is unsubstituted orsubstituted on ring carbon atoms by one or more identical or differentsubstituents R³²; R³² is selected from the group consisting of halogen,(C₁-C₄)-alkyl, hydroxy, oxo, (C₁-C₄)-alkyl-O— and cyano; and m isselected from the group consisting of 0, 1 and 2, wherein all numbers mare independent of each other and can be identical or different; whereinHet is a monocyclic, 4-membered to 6-membered, saturated heterocyclicgroup comprising 1 or 2 identical or different hetero ring membersselected from the group consisting of N, N(R⁴⁰) and O, and which isunsubstituted or substituted on ring carbon atoms by one or moreidentical or different substituents selected from the group consistingof fluorine and (C₁-C₄)-alkyl; and wherein each alkyl group,independently of any other substituents which can be present on an alkylgroup, is optionally substituted by one or more fluorine substituents.3. The compound of formula I according to claim 1, or a pharmaceuticallyacceptable salt thereof, wherein: A is selected from the groupconsisting of phenyl and a monocyclic, 5-membered or 6-membered,aromatic heterocyclic group, wherein the aromatic heterocyclic groupcomprises 1 or 2 identical or different hetero ring members selectedfrom the group consisting of N, N(R²⁰), O and S, and is bonded via aring carbon atom, and wherein the phenyl and the aromatic heterocyclicgroup are unsubstituted or substituted on ring carbon atoms by one ormore identical or different substituents R²¹; E is a direct bond or achain consisting of 1 to 4 chain members of which 0, 1 or 2 chainmembers are identical or different hetero chain members selected fromthe group consisting of N(R²⁵) and O, and the other chain members areidentical or different groups C(R²⁶)(R²⁷); G is selected from the groupconsisting of hydrogen, (C₁-C₄)-alkyl and R³⁰; R¹ and R⁴ areindependently selected from the group consisting of hydrogen, halogenand (C₁-C₃)-alkyl; R² is selected from the group consisting of hydrogen,halogen and (C₁-C₃)-alkyl; R³ and R⁶ are independently selected from thegroup consisting of hydrogen, halogen and C₁-alkyl; R⁵ is selected fromthe group consisting of hydrogen, halogen, (C₁-C₄)-alkyl and cyano; R¹⁰is selected from the group consisting of hydrogen, (C₁-C₆)-alkyl and(C₃-C₇)-cycloalkyl, wherein the (C₁-C₆)-alkyl group is unsubstituted orsubstituted by 1 substituent selected from the group consisting of(C₃-C₇)-cycloalkyl, Het, cyano and (C₁-C₄)-alkyl-O—, and wherein each(C₃-C₇)-cycloalkyl is unsubstituted or substituted by one or moreidentical or different substituents selected from the group consistingof fluorine and (C₁-C₄)-alkyl; R²⁰, R²², R²⁵, R³¹ and R⁴⁰ areindependently selected from the group consisting of hydrogen and(C₁-C₄)-alkyl; R²¹ is selected from the group consisting of halogen,(C₁-C₄)-alkyl, (C₁-C₄)-alkyl-O— and cyano, or two groups R²¹ attached toadjacent ring carbon atoms in group A are taken together with the carbonatoms to which they are attached to form a 5-membered or 6-memberedmono-unsaturated ring comprising 0, 1 or 2 identical or different heteroring members selected from the group consisting of N(R²²) and O, andwhich is unsubstituted or substituted on ring carbon atoms by one ormore identical or different substituents selected from the groupconsisting of fluorine and C₁-alkyl; R²⁶ and R²⁷ are independentlyselected from the group consisting of hydrogen, fluorine, (C₁-C₃)-alkyland hydroxy, and in one group C(R²⁶)(R²⁷), the substituents R²⁶ and R²⁷attached to the same carbon atom are optionally taken together to formoxo; R³⁰ is a monocyclic or bicyclic, 3-membered to 10-membered ring,which is saturated or aromatic and comprises 0, 1 or 2 identical ordifferent hetero ring members selected from the group consisting of N,N(R³¹), O and S(O)_(m), and which is unsubstituted or substituted onring carbon atoms by one or more identical or different substituentsR³²; R³² is selected from the group consisting of halogen,(C₁-C₄)-alkyl, hydroxy, oxo and (C₁-C₄)-alkyl-O—; and m is selected fromthe group consisting of 0, 1 and 2, wherein all numbers m areindependent of each other and can be identical or different; wherein Hetis a monocyclic, 4-membered to 6-membered, saturated heterocyclic groupcomprising 1 hetero ring member selected from the group consisting ofN(R⁴⁰) and O, and which is unsubstituted or substituted on ring carbonatoms by one or more identical or different substituents selected fromthe group consisting of fluorine and (C₁-C₃)-alkyl; and wherein eachalkyl group, independently of any other substituents which can bepresent on an alkyl group, is optionally substituted by one or morefluorine substituents.
 4. The compound of formula I according to claim1, or a pharmaceutically acceptable salt thereof, wherein: A is selectedfrom the group consisting of phenyl and a monocyclic, 5-membered or6-membered, aromatic heterocyclic group, wherein the aromaticheterocyclic group comprises 1 or 2 identical or different hetero ringmembers selected from the group consisting of N, N(R²⁰) and S, and isbonded via a ring carbon atom, and wherein the phenyl and theheterocyclic group are unsubstituted or substituted on ring carbon atomsby one or more identical or different substituents R²¹; E is a directbond or a chain consisting of 1 to 4 chain members of which 0 or 1 chainmembers are identical or different hetero chain members selected fromthe group consisting of N(R²⁵) and O, and the other chain members areidentical or different groups C(R²⁶)(R²⁷); G is selected from the groupconsisting of hydrogen and R³⁰; R¹ and R⁴ are independently selectedfrom the group consisting of hydrogen, halogen and (C₁-C₂)-alkyl; R² isselected from the group consisting of hydrogen, halogen and(C₁-C₂)-alkyl; R³ and R⁶ are independently selected from the groupconsisting of hydrogen, halogen and C₁-alkyl; R⁵ is selected from thegroup consisting of hydrogen, halogen and (C₁-C₂)-alkyl; R¹⁰ is selectedfrom the group consisting of hydrogen, (C₁-C₄)-alkyl and(C₃-05)-cycloalkyl, wherein the (C₁-C₄)-alkyl group is unsubstituted orsubstituted by 1 substituent selected from the group consisting of(C₃-C₅)-cycloalkyl and Het, and wherein each (C₃-C₅)-cycloalkyl group isunsubstituted or substituted by one or more identical or differentsubstituents (C₁-C₂)-alkyl; R²⁰, R²⁵ and R³¹ are independently selectedfrom the group consisting of hydrogen and (C₁-C₃)-alkyl; R²¹ is selectedfrom the group consisting of halogen, (C₁-C₄)-alkyl, (C₁-C₄)-alkyl-O—and cyano; R²⁶ and R²⁷ are independently selected from the groupconsisting of hydrogen, fluorine, C₁-alkyl and hydroxy, and in one groupC(R²⁶)(R²⁷), the substituents R²⁶ and R²⁷ attached to the same carbonatom are optionally taken together to form oxo; R³⁰ is a monocyclic3-membered to 6-membered or bicyclic 9-membered to 10-membered ring,which is saturated or aromatic and comprises 0, 1 or 2 identical ordifferent hetero ring members selected from the group consisting of N,N(R³¹) and O, and which is unsubstituted or substituted on ring carbonatoms by one or more identical or different substituents R³²; and R³² isselected from the group consisting of halogen, (C₁-C₃)-alkyl, hydroxyand oxo; wherein Het is a monocyclic, 4-membered or 5-membered,saturated heterocyclic group comprising 1 hetero ring member which is 0,and which is unsubstituted or substituted on ring carbon atoms by one ormore identical or different substituents (C₁-C₃)-alkyl; and wherein eachalkyl group, independently of any other substituents which can bepresent on an alkyl group, is optionally substituted by one or morefluorine substituents.
 5. The compound of formula I according to claim1, or a pharmaceutically acceptable salt thereof, wherein: A is selectedfrom the group consisting of phenyl, pyrazolyl and pyridinyl, each ofwhich is unsubstituted or substituted on ring carbon atoms by one ormore identical of different substituents R²¹; E is a direct bond or achain consisting of 1 to 3 chain members of which 0 or 1 chain member isa hetero chain member which is O, and the other chain members areidentical or different groups C(R²⁶)(R²⁷); G is selected from the groupconsisting of hydrogen and R³⁰; R¹ and R⁴ are independently selectedfrom the group consisting of hydrogen, halogen and C₁-alkyl; R² isselected from the group consisting of hydrogen, halogen and C₁-alkyl; R³and R⁶ are each hydrogen; R⁵ is selected from the group consisting ofhalogen and (C₁-C₂)-alkyl; R¹⁰ is selected from the group consisting ofhydrogen, (C₁-C₄)-alkyl and (C₃-C₅)-cycloalkyl, wherein the(C₁-C₄)-alkyl group is unsubstituted or substituted by 1 substituentselected from the group consisting of (C₃-C₅)-cycloalkyl and Het; R²¹ isselected from the group consisting of halogen, (C₁-C₄)-alkyl,(C₁-C₄)-alkyl-O— and cyano; R²⁶ and R²⁷ are independently selected fromthe group consisting of hydrogen, fluorine and C₁-alkyl; R³⁰ is amonocyclic, 3-membered to 6-membered ring, which is saturated oraromatic and comprises 0, 1 or 2 identical or different hetero ringmembers selected from the group consisting of N, N(R³¹) and O, and whichis unsubstituted or substituted on ring carbon atoms by one or moreidentical or different substituents R³²; R³¹ is selected from the groupconsisting of hydrogen and (C₁-C₃)-alkyl; and R³² is selected from thegroup consisting of halogen and (C₁-C₃)-alkyl; wherein Het is amonocyclic, 4-membered or 5-membered, saturated heterocyclic groupcomprising 1 hetero ring member which is O, and which is unsubstitutedor substituted on ring carbon atoms by one or more identical ordifferent substituents (C₁-C₃)-alkyl; and wherein each alkyl group,independently of any other substituents which can be present on an alkylgroup, is optionally substituted by one or more fluorine substituents.6. The compound of formula I according to claim 1, or a pharmaceuticallyacceptable salt thereof, wherein: A is phenyl, which is unsubstituted orsubstituted on ring carbon atoms by one or more identical or differentsubstituents R²¹; E is a direct bond; and G is selected from the groupconsisting of hydrogen, halogen, (C₁-C₄)-alkyl and cyano.
 7. Thecompound of formula I according to claim 1, or a pharmaceuticallyacceptable salt thereof, wherein: A is phenyl, which is unsubstituted orsubstituted on ring carbon atoms by one or more identical or differentsubstituents R²¹; E is a chain consisting of 1 to 5 chain members ofwhich 0, 1 or 2 chain members are identical or different hetero chainmembers selected from the group consisting of N(R²⁵), O and S(O)_(m),and the other chain members are identical or different groupsC(R²⁶)(R²⁷); and G is R³⁰.
 8. The compound of formula I according toclaim 1, or a pharmaceutically acceptable salt thereof, wherein: A is amonocyclic or bicyclic, 5-membered to 10-membered, aromatic heterocyclicgroup comprising 1 or 2 identical or different hetero ring membersselected from the group consisting of N, N(R²⁰), O and S, and is bondedvia a ring carbon atom, and which is unsubstituted or substituted onring carbon atoms by one or more identical of different substituentsR²¹; E is a direct bond; and G is selected from the group consisting ofhydrogen, halogen, (C₁-C₄)-alkyl and cyano.
 9. The compound of formula Iaccording to claim 1, or a pharmaceutically acceptable salt thereof,wherein: A is a monocyclic or bicyclic, 5-membered to 10-membered,aromatic heterocyclic group comprising 1 or 2 identical or differenthetero ring members selected from the group consisting of N, N(R²⁰), Oand S, and is bonded via a ring carbon atom, and which is unsubstitutedor substituted on ring carbon atoms by one or more identical ordifferent substituents R²¹; E is a chain consisting of 1 to 5 chainmembers of which 0, 1 or 2 chain members are identical or differenthetero chain members selected from the group consisting of N(R²⁵), O andS(O)_(m), and the other chain members are identical or different groupsC(R²⁶)(R²⁷); and G is R³⁰.
 10. The compound of formula I according toclaim 1, which is selected from the group consisting of:6-Bromo-9-ethyl-1-methyl-8-(1-pyridin-3-ylmethyl-1H-pyrazol-4-yl)-9H-pyrido[3,4-b]indole;6-Chloro-1,5-dimethyl-8-[4-(3-methyl-oxetan-3-ylmethoxy)-phenyl]-9H-pyrido[3,4-b]indole;2-(4-[6-Chloro-9-(2,2,2-trifluoroethyl)-9H-pyrido[3,4-b]indol-8-yl]pyrazol-1-yl)ethanol;6-Chloro-1-methyl-8-[4-(2-pyrazol-1-ylethoxy)-phenyl]-9H-pyrido[3,4-b]indole;6-Bromo-9-ethyl-1,3-dimethyl-8-(1-methyl-1H-pyrazol-4-yl)-9H-pyrido[3,4-b]indole;6-Chloro-8-(4-methoxy-phenyl)-1,9-dimethyl-9H-pyrido[3,4-b]indole;6-Chloro-8-(4-methoxy-phenyl)-1,5-dimethyl-9H-pyrido[3,4-b]indole;8-(4-Methoxy-phenyl)-1-methyl-9H-pyrido[3,4-b]indole-6-carbonitrile;6-Chloro-1-methyl-8-[4-(1-methyl-1H-imidazol-2-ylmethoxy)-phenyl]-9H-pyrido[3,4-b]indole;6-Chloro-1,5-dimethyl-8-[4-(2-pyrazol-1-yl-ethoxy)-phenyl]-9H-pyrido[3,4-b]pyridine;6-Chloro-9-cyclopropylmethyl-8-(2,6-dichloro-pyridin-3-yl)-9H-pyrido[3,4-b]indole;6-Chloro-8-(2,6-dichloro-pyridin-3-yl)-9-ethyl-9H-pyrido[3,4-b]indole;8-(2,6-Dichloro-pyridin-3-yl)-1,6-dimethyl-9H-pyrido[3,4-b]indole;6-Chloro-9-ethyl-1-methyl-8-(1-pyridin-3-ylmethyl-1H-pyrazol-4-yl)-9H-pyrido[3,4-b]indole;6-Chloro-8-(4-chloro-phenyl)-9-ethyl-1-methyl-9H-pyrido[3,4-b]indole;6-Chloro-8-(4-methoxy-phenyl)-1-methyl-9H-pyrido[3,4-b]indole;6-Chloro-8-chroman-6-yl-1-methyl-9H-pyrido[3,4-b]indole;6-Chloro-8-[4-(2-imidazol-1-yl-ethoxy)-phenyl]-1-methyl-9H-pyrido[3,4-b]indole;6-Bromo-9-ethyl-1-methyl-8-(1-methyl-1H-pyrazol-4-yl)-9H-pyrido[3,4-b]indole;4-(6-Chloro-1-methyl-9H-pyrido[3,4-b]indol-8-yl)-pyridin-2-ylamine;6-Chloro-1-methyl-8-[4-(1-methyl-pyrrolidin-3-ylmethoxy)-phenyl]-9H-pyrido[3,4-b]indole;6-Chloro-9-ethyl-1-methyl-8-[4-(3-methyl-oxetan-3-ylmethoxy)-phenyl]-9H-pyrido[3,4-b]indole;6-Bromo-9-ethyl-1-methyl-8-[4-(3-methyl-oxetan-3-ylmethoxy)-phenyl]-9H-pyrido[3,4-b]indole;and6-Chloro-9-cyclopropylmethyl-8-(1-pyridin-3-ylmethyl-1H-pyrazol-4-yl)-9H-pyrido[3,4-b]indole,or a pharmaceutically acceptable salt thereof.
 11. A process forpreparing the compound of formula I according to claim 1, comprising:

reacting a compound of formula II with a compound of formula III,wherein: A, E, G, le to R⁶ and R¹⁰ in the compounds of formulae II andIII are defined as in the compound of formula I, or functional groupsare present in protected form or in the form of a precursor group; X inthe compound of formula II is a leaving group; and each Y in thecompound of formula III is independently hydrogen or (C₁-C₄)-alkyl, ortwo groups Y are taken together with the —O—B—O— moiety to which theyare attached to form a saturated 5-membered or 6-membered ringcomprising 2 or 3 carbon atoms as ring atoms in addition to the —O—B—O—moiety, and is unsubstituted or substituted by one or more (C₁-C₄)-alkylsubstituents, to form the compound of formula I.
 12. A pharmaceuticalcomposition comprising the compound of formula I according claim 1, or apharmaceutically acceptable salt thereof, and a pharmaceuticallyacceptable carrier.